


S H 

167 
•S5tl5 



U. S. COMMISSION OF FISH AND FISHERIES,. 
GEORGE M. BOWERS, Commissioner. 



ARTIFICIAL PROPAGATION 



OF THE 



SHAD AND PIKE PERCH. 



Extracted from the Revised Edition of the Fish Manual. Pages 121-145 and 165-179 
Plates 40-46 and 51-52. 



WASHINGTON: 

GOVERNMENT PRINTING OFFICE. 
1903. 




Glass . SH^fet 
Book >3^Jl5_. 



U. S. COMMISSION OF FISH AND FISHERIES, 

GEORGE M. BOWERS, Commissioner. 



ARTIFICIAL PROPAGATION 



OF THE 



SHAD AND PIKE PERCH. 



Extracted from the Revised Edition of the Fish Manual. Pages 121-145 and 165-179 
Plates 40-46 and 51-52. 



WASHINGTON: 

GOVERNMENT PRINTING OFFICE. 

1903. 



24 1907 






Digitized by the Internet Archive 
in 2011 with funding from 
The Library of Congress 



http://www.archive.org/details/artificialpropag04unit 



Fish Manual. (To face page 121. 



Plate 40 




THE SHAD. 



DESCRIPTION OF THE SHAD. 

The shad (Alosa sapidissima) is the largest, best-known, and most 
valuable member of the herring family in the United States. The body 
is deep and compressed, the depth varying with the sex and spawning- 
condition, but averaging about one-third the body length. The head, 
contained about 4^ times in the body length, is quite deep; the cheek 
is deeper than long. The jaws are about equal, the lower jaw fitting 
into a deep notch on the tip of the upper. Teeth are present in the 
young, but are not found on the jaws in the adult. The eye is contained 
5| to 6 times in the length of head. The gillrakers are long, slender, 
and numerous, there being from 93 to 120 on the first arch. The fins 
are small and weak, the dorsal containing 15 rays and the anal 21. 
The lower edge of the body is strongly serrated, the plate-like scales 
numbering 21 before the ventral fin and 16 behind it. The scales in 
the lateral line number 60. The body is dark-bluish or greenish above, 
silvery on the sides, and white beneath. There is a dark spot behind 
the gill-opening and sometimes a row of smaller spots along the side. 
The vertical fins often have black or dusky edges. The peritoneum 
is white. Supposed structural and color peculiarities in shad from 
different regions or basins have not been verified. 

From the other clupeoids with which the shad is frequently asso- 
ciated in the rivers, it may be readily distinguished. In all of them the 
cheek is longer than deep. The hickory shad or hickory jack (Pomolobus 
mediocris) has a projecting lower jaw and a very straight profile. The 
river herrings or alewives are much smaller than the shad, have fewer 
and shorter gillrakers, and a larger eye (3 J in head). In the branch 
herring (P. pseudoharengus) the peritoneum is pale, while in the glut 
herring (P. cestivalis) it is black. 

The female shad is larger than the male, the average difference in 
weight being more than a pound. The mature males taken in the 
fisheries of the Atlantic coast weigh from 1£ to 6 pounds, the average 
being about 3 pounds; the females usually weigh from 3 to 6 pounds, 
the average being If pounds. The general average for both sexes is 
between 3| and 4 pounds. In the early history of the fisheries, shad 
weighing 11, 12, and even 14 pounds were reported, but 9-pound shad 
are very rare on the Atlantic coast, and 10 pounds seems to be the 
maximum. Some seasons an unusual number of large shad (7 to 9 
pounds) appear in certain streams. On the Pacific coast shad average 
a pound or more heavier than on the Atlantic, occasionally attaining a 
weight of 14 pounds ; many have been reported weighing 9 to 12 pounds. 

121 



122 REPORT OP COMMISSIONER OF FISH AND FISHERIES. 
DISTRIBUTION AND ABUNDANCE. 

The shad is distributed along the entire east coast of the United 
States, and northward and eastward to the Gulf of St. Lawreuce. It 
has gradually spread from the Sacramento River, California, where it 
was introduced by the California Fish Commission, and is now taken 
from southern California (Los Angeles County) to southeast Alaska. 
In the early history of the country its abundance excited unbounded 
astonishment. Nearly every river on the Atlantic coast was invaded in 
the spring by immense schools, which, in their upward course, furnished 
an ample supply of good food. Notwithstanding greatly increased fish- 
ing operations and the curtailment of the spawning-grounds, the supply 
in recent years has not only been generally maintained, but owing to 
fish-cultural efforts has been largely augmented in certain streams, 
notably in the Kennebec, Hudson, Delaware, Susquehanna, Choptank, 
Potomac, Nanticoke, Rappahannock, York, James, Chowan, Eoanoke, 
Neuse, and St. Johns rivers, and in Chesapeake Bay, Albemarle Sound, 
Croatan Sound, and Pamlico Sound, and the Sacramento and Columbia 
rivers. 

SHAD IN THE OCEAN. 

The shad passes most of its existence at sea, and little is known of 
its habits and movements when out of the rivers. The ocean areas to 
which it resorts are unknown, and what its salt-water food consists 
of has not been determined. In the Gulf of Maine it is known to 
associate in large numbers with mackerel and herring during the 
months of June, September, and October, being most numerous in June. 
It has been taken at North Truro, Massachusetts, in the fall, when the 
ocean temperature was from 43° to 49°. In the month of November, 
one year after another, it has been found on the west side of Sakonnet 
River, Rhode Island. In May and June it has been captured with 
mackerel a few miles northeast of Cape Cod Light. Some instances 
of capture indicate that under certain conditions the adults may 
remain in the fresh-water rivers a whole year. In November, 1890, 600 
were taken in the Chesapeake Bay. It has been found in the Potomac 
in considerable abundance in August and September, and even during 
the last week in December. Its movements are largely controlled by 
the water temperature. It is believed that it seeks to occupy an area 
having a temperature of 60° or 70°, and that its migrations are deter- 
mined by the shifting of this area. 

SHAD IN THE RIVERS. 

The annual migration of the shad from the ocean to the rivers is 
for the sole purpose of reproduction. It ascends to suitable spawning- 
grounds, which are invariably in fresh water, occupying several weeks 
in depositing and fertilizing its eggs in any given stream. 

Its migrations from the sea are in quite a regular succession of 
time with relation to latitude. It first appears in the St. Johns River, 



MANUAL OF FISH-CULTURE. i23 

Florida, about November 15, the season of greatest abundance being 
February and March. In the Savannah Eiver, Georgia, and the Edisto, 
South Carolina, the run begins early in January and ends the last of 
March. In the North Carolina rivers these stages of the migration are 
a little later. In the Potomac Eiver advance individuals appear late 
in February, but the fish is most numerous in April. In the Delaware 
River the maximum run is about the 1st of May. It reaches the Hud- 
son River the last of March, and is found in the Connecticut toward 
the end of April, is most abundant the last of May, and leaves the 
stream late in July. In the Kennebec and Androscoggin rivers, Maine, 
it is first taken m April and has left by the middle of July. In the Sfc. 
John River, New Brunswick, it appears about the middle of May, and 
in the- Miramichi River, New Brunswick, late in May. 

The main body of shad ascends the rivers when the temperature of 
the water is from 56° to 66°, the numbers diminishing when the tem- 
perature is over 66°. Successive schools enter the Potomac from 
February to July, the males preceding the females. Of 61,000 shad 
comprising the first of the run received at Washington, D. C, from 
March 19 to 24, 1897, 90 per cent were males. Toward the close of the 
season males are extremely scarce. 

The movement of the shad up the rivers is not constant, but in 
waves, causing a rise and fall in the catch. In some of the rivers the 
fishermen claim that a fairly well-defined run occurs late in the season, 
consisting of a somewhat different fish, known as "May shad." 

The erection of impassable dams along the rivers and streams was 
probably the first thing to curtail the natural spawning- grounds of 
these fish and to seriously check their natural increase. 

As shad enter the rivers only for the purpose of spawning, the 
fisheries are necessarily prosecuted during the spawning season, and 
often upon the favorite spawning-grounds. The increase of population 
necessitates a larger supply of fish and requires the use of more 
apparatus, and the number of shad that reach fresh water is therefore 
greatly curtailed by assiduous fishing with all kinds of contrivances in 
the estuaries and in the mouths and lower parts of rivers. Under these 
conditions of a restricted spawning area and increased netting shad 
would soon be exterminated without artificial propagation ; or the fish- 
ery, at least, would greatly diminish and become unprofitable. Such a 
crisis was fast approaching in 1879, when the Fish Commission entered 
upon systematic work in shad propagation. 

From their birth until their return to the rivers shad are preyed 
upon incessantly by other fish, so that the larger portion of the young 
do not survive their few months' sojourn in fresh water, and of those 
which leave the rivers each season probably not one in one hundred 
reaches maturity to deposit its eggs and contribute to the perpetuation 
of its species. In the rivers striped bass, white perch, black bass, and 
other predaceous fishes devour the young, and when they reach salt 
water, sharks, horse mackerel, kingfish, etc., undoubtedly destroy many 



124 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 

adults. It has been observed by North Carolina porpoise fishermen 
that as the shad swim close along the shore the porpoises follow and ; 
feed on them till they pass into fresh water. In the rivers the adult 
shad is comparatively free from enemies. 

To what extent the pollution of the waters has reduced the numbers 
of shad is not known, but acids, sawdust, garbage, oils, gas tar, and 
refuse from dye-works all tend to make the water of rivers unsuitable 
for them. 

FOOD. 

After entering the rivers, the shad takes but little, if any, food 
previous to spawning, but after casting its eggs it bites at flies or aiiy 
small shining object, and has been known to take the artificial fly. 
The mouth of the adult is practically toothless, and its throat contains 
no functionally active teeth. The water which passes through the 
branchial filter — the gillrakers — is deprived of the small animals which 
are too large to pass through its meshes. It is a common remark with 
fishermen and others that food is rarely found in the stomach of the 
adult shad in fresh water, but examinations have shown that the shad 
does, in some instances, eat small Crustacea, insects, etc. The only 
substance commonly found in its stomach in fresh water has the 
appearance of black mud. It is held by some that the shad swims 
with its mouth open and may unintentionally swallow the small organ- 
isms found in its stomach under such circumstances, but as far as 
observation of fish in aquaria and experiences of net fishermen go, the 
shad does not swim with its mouth open. 

NATURAL SPAWNING. 

Shad are liable to be ripe anywhere above brackish water, and under 
favorable temperature conditions spawn wherever they happen to be, 
but in some river basins they exhibit a well defined choice of spawning- 
places, preferring localities below the mouths of creeks, where the 
warmer water of creeks mingles with the colder channel water. The 
shad lays its eggs during the highest daily average temperature, a con- 
dition realized about sunset, when the warmer shoal water commingles 
with the colder channel water, establishing a balance. The principal 
spawning occurs from 5 p. m. to 10 p. m. Observations on the Potomac 
liiver show that of the eggs from shad caught in a seine only 11 per 
cent were taken between midnight and noon, the percentage in the 
morning being 14 one year and 8 another. 

The eggs in the ovaries remain in a compact mass until they ripen, 
at first occupying but a small space, but gradually increasing until 
they distend the whole abdomen, the average weight of the ovaries being 
about 13 ounces. Close examination at the approach of the spawning 
time will disclose large maturing eggs of rather uniform size and others 
smaller and of variable size. Whether the latter are the forming eggs 
for the next year, for two or three succeding years, or for the lifetime of 
the fish has not been determined, nor is it known whether shad spawn 
every year. The small and shrunken ovaries of a spent fish are still 



Fish Manual. (To face page 124.) 



Plate 41 , 




A. Freshly extruded egg enlarged, showing its envelope much wrinkled and its surface covered with 
small round vesicles. 

B. Shad egg, showing vitellus and distended egg-membrane, natural size. 

C. Shows the gradual accumulation of germinal matter at one pole of egg, the polar prominence ex- 
ternally, and presence of plasmic processes extending down through the vitellus. 

D. Embryo shad in its natural position in its spacious enveloping membrane. From a photograph. 

E. Diagrammatic representation of an embryo to show course of segmental ducts sd and extension 
outward of pectoral plates pp, which are intimately concerned in the development of pectoral fins. 

F. Side view of a young shad 13 days old, viewed as a transparent object, ab, rudimentary air- 
bladder; L, liver; Gb, gall-bladder. 

G. An embryo in its envelope, on the third day of development, nearly ready to hatch. 



Fish Manual. (To face page 124.) 



Plate 42. 




H and /. Two views of an egg after the blastoderm has spread considerably and the embryonic area e is 
well defined. 

K. View of nnhatched embryo, which developed in a temperature of 45° F., producing distortions of tail 
and notochord. 

L. An egg-envelope with its contained embryo, forty-four hours after impregnation, viewed as a trans- 
parent object. 

M. An egg-envelope with its contained embryo at the beginning of the third day of development. From 
a photograph. 

N. Anterior portion of a young fish on fourth day. To show relations of liver L to yolk Y, over which 
the portal vessel pv passes forward to empty into the venous sinus, in common with the anterior and 
posterior jugulars j' and j, ba bulbus aorta?, ve ventricle. 

O. View of fore part of a young fish 17 days old, from ventral side. 



Plate 43. 




P. Young fish immediately after hatching, viewed as an opaque object and somewhat obliquely from one side, 
to display the relations of branchial and hyomandibular arches, and position of pectoral fin. 

Q. Young fish third day after hatching, viewed as a transparent ooject to show extension of segmental duct 
forward; chorda ch. 

R. Young fish 5 days after hatching, very much enlarged, and viewed as an opaque object. Only a slight rem- 
nant of the yolk-sac Y remains. 

S. Young fish 1? days after hatching, viewed partly as an opaque and partly as a transparent object; py pylorus 
and rudimentary air-bladder above it; I intestine, filled with the remains of ingested food. The opercula are 
already so far developed as partly to conceal the gills. 



MANUAL OF FISH-CULTURE. 125 

found full of these eggs of different sizes. Shortly before spawning, 
transparent eggs of large size, contrasting strongly with the opaque 
golden hue of less mature ones, will be found scattered through the still 
compact ovarian mass, and, becoming more and more numerous, the 
ovaries disintegrate, the eggs fall apart, and extrusion begins, a liquid 
stream of eggs and mucus flowing from the oviduct on the slightest 
pressure of the abdomen. 

Freshly deposited shad eggs are of a pale amber or pink color, and 
are transparent. They are about ,\ inch in diameter and somewhat 
flattened and irregularly rounded in form. The egg membrane is much 
wrinkled and lies in close contact with the contained vitellus. Imme- 
diately after fertilization the egg becomes spherical through the absorp- 
tion of water and apparently gains very much in bulk, measuring about 
y of an inch in diameter; but this gain is only the distended egg mem- 
brane, the vitellus or true germinal and nutritive portion not having 
increased. The vitellus is heavier than water, and a large space filled 
with fluid now exists between it and the membrane, the vitellus rolling 
about and changing its position as the position of the egg membrane is 
altered. No adhesive material is found on the outside of the membrane, 
though when first extruded the eggs are covered with a somewhat sticky 
ovarian mucus. 

In a state of nature the shad deposits its eggs loosely in the rivers 
without building a nest, the two sexes running along together from 
the channel towards the shore, and the eggs and milt being ejected 
simultaneously. On quiet evenings, at the height of the season, 
spawning shad may be heard surging and plunging along the shores. 
By fishermen this is termed "washing." 

Shad are very prolific, but much less so than many other food-fishes. 
The quantities of eggs taken by spawn-takers do not represent the 
actual fecundity, for many are cast in advance of stripping. The 
average number is not more than 30,000. Single fish have been known 
to yield 60,000, 80,000, 100,000, and 115,000 eggs; and on the Delaware 
River, in 1885, one yielded 156,000. Many eggs fail to be fertilized, 
and but a comparatively small percentage of those impregnated are 
hatched. After being extruded, the eggs sink to the bottom, where 
they remain until hatched, subject to the attacks of fish and other 
water animals. Eels are very destructive to shad spawn and often 
attack shad caught in gill nets, devouring the undeposited eggs and 
sometimes mutilating half the catch of a gill net fisherman. 

The development of fungus is one of the greatest dangers to shad 
eggs in a natural state, and another potent agency for their destruction 
is the mud brought down by heavy rains, burying and suffocating 
the eggs. 

After spawning, shad are denominated "down -runners," "racers,'' 
and "spent fish." They are then very lean and hardly fit for food, but 
they begin to feed and have become fatter by the time they reach salt 
water in the summer or fall. 



126 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 

YOUNG SHAD. 

In the Middle States the young fish remain in the rivers, feeding 
and growing, until the cool weather of fall comes on. They then 
i begin to drop" downstream, and by the last of November have passed 
out into the ocean or bays, and are lost sight of until they come back 
three or four years after, full-grown and ready to spawn. They leave 
the Potomac Biver when the water falls to about 40°. By that time 
they are about 3 inches long. For the last two or three years they 
have been observed in great abundance about Bryan Point, feeding and 
jumping out of the' water about sunset. They keep within the open 
streak of water between the shores and the water-grass which covers 
the flats, in water 2 to 5 feet deep. After mild winters young shad have 
been found in the Potomac Biver in April, 30 miles above brackish 
water and 160 miles from the ocean, associated with young alewives and 
sturgeon. Some immature shad, apparently 2 years old, are caught 
each year in seines operated in the fresh water of the Potomac Biver, 
and undersized shad are frequently caught in the New England rivers, 
where the tidal waters are of little length. 

COMMERCIAL VALUE. 

The shad is one of the most palatable and popular of fishes. Its 
flesh is rich, but not oily, and the roe is considered a delicacy. It is 
the most valuable river fish of the Atlantic coast, and, next to the 
Pacific salmon, the most important species inhabiting the fresh waters 
of North America. In every Atlantic State from New Jersey to Florida, 
inclusive, it is the most valuable fish, and in New York it is second only 
: to the bluefish. Among all the economic fishes of the United States 
only the salmon and cod exceed it in value, and, considering all branches 
of the fishing industry, only the whale fishery and the oyster fishery, 
besides the foregoing, are financially more important than the shad. 

In 1896 the shad catch of the Atlantic seaboard numbered 13,145,395 

fish, weighing 50,847,967 pounds, and worth to the flshermeu $1,656,580. 

The value of the shad catch of the Pacific States in 1895 was $5,600, a 

sum representing 366,000 pounds. 
i 

EARLY ATTEMPTS AT SHAD- CULTURE. 

The systematic development and extension of shad-culture were 
undertaken with the definite purpose of testing the value of artificial 
propagation in maintaining an important fishery which was being 
rapidly depleted. As early as 1848 shad eggs were artificially taken 
and fertilized, and in 1867 more extensive experiments were made on 
the Connecticut Biver, and later on the Potomac, with encouraging 
results. The attention of many States was thus attracted to the work, 
! and in 1872 it was taken up by the general government. Prior to the 
experiments on the Connecticut, certain species of the salmon family 
had been principally dealt with in fish-culture, and different methods 
from those in use were necessary for shad-hatching, owing to the less 
specific gravity of shad ova and the much shorter period of time 
required for the development of the fish from the egg. 



MANUAL OF FISH-CULTURE. 127 

The "Seth Greeu box," a modification of the floating-box used for 
hatching trout and salmon eggs, was first tried with great success, but 
floating-boxes were subject to various accidents when used in tidal 
waters, and in rapid succession devices of various kinds were brought ' 
forward to supplant them. The most important were hatching-cones* 
and the plunger-buckets, which, though imperfect, rendered larger 
operations possible. At this period the apparatus was arranged on 
flat-bottomed barges and towed from point to point along tbe coast from 
Albemarle Sound to the Susquehanna Biver, a slow and expensive 
method. The Chase whiteflsh jar worked with considerable efficiency, 
but required modifications, and finally the u universal" hatching jar now 
in use was adopted in 1882. 

During the years of experimental work from 1872 to 1880, 97,471,700 
shad fry were planted, beginning with 859,000 in 1872, while in 1880, 
28,626,000 were distributed. Prior to 1880 deposits of a few hundred 
thousand each were made in as many different streams as possible, but 
the increased production of young fish made it possible to ship and 
plant the fry by the carload, and by 1884 shad-culture was established 
on a large scale, barge operations were abandoned, and the work 
conducted on shore. The basins of the Chesapeake Bay and Delaware 
Eiver had meanwhile been selected by the United States Commission 
as the natural seat of operations, though the State commissions from 
Massachusetts to South Carolina were actively engaged on their own 
account. At present the States, except Connecticut, New York, Penn- 
sylvania; and Maryland, have practically abandoned shad-hatching, 
leaving the work to the general government. 

EGG-GROUNDS. 

Every river on the Atlantic coast from Massachusetts southward has 
been examined by the agents of some State commission or the United 
States, or by botb,in order to determine the natural spawning-grounds 
of the shad. On nearly every stream hatcheries have been operated 
at one time or another, but usually eggs were not obtained in sufficient 
numbers to justify continued operations, except in the Chesapeake and 
Delaware basins. However, it is not unlikely that after further investi- 
gation it will be found practicable to maintain hatcheries on rivers 
which have long since been abandoned. It is certain that work on the 
Albemarle Sound can be successfully conducted, and though operations 
on the Hudson Eiver nave not been on a large scale, better results may 
be there obtained in the future. 

In certain river stretches, apparently favorable, no ripe fish are found; 
for example, in the Eoanoke Eiver for 15 miles above its mouth, where 
10,000 to 15,000 shad are taken annually, mature eggs can not be found, 
though the fish spawn just below there, as they do many miles above at 
Weldon. In the Sutton Beach seine, the one in North Carolina waters 
which has afforded the most spawn, only about one spawning shad to 
each 100 is caught, and the annual catch of this seine is 30,000 to 75,000 
per annum. In view of such facts, it is not remarkable tbat difficulty 



128 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



has been experienced and time consumed in deciding on permanent loca- 
tions for hatcheries. 

The spawning period varies widely in different seasons ; in some years 
shad are numerous and in spawning condition two or three weeks after 
the time when they have ordinarily disappeared. They deposit eggs at 
some point along the coast for six continuous months. 

The following streams have been occupied by hatcheries, as some of 
them are now, and it will be observed that the approximate spawning 
periods, beginning early in the South, become gradually later toward 
the North. 



Waters. 


Place. 


Period. 






Mar. 5-26. 

Apr. 1-30. 

Apr. 15 to June 10. 

Apr. 17 to June 15. 

May 10 to June 20. 

May 15 to June 30. ! 

Do. 
June 15 to July 5. 
June 1 to Julv 15. 








Below Washington, D. C - 

Below Havre cle Grace, Md . . . 


























. 









The United States Fish Commission operates stations at Bryan 
Point, 12 miles below Washington on the Potomac, and at Battery 
Island at the mouth of the Susquehanna, while the steamer Fish Hawk. 
fitted up as a floating hatchery, is engaged during the shad season on 
the Delaware River. These two stations and the vessel can receive 
respectively 16,000,000, 40,000,000, and 12,000,000 eggs. On more than 
one occasion each has been taxed to its utmost capacity, but as the 
average hatching period is 8 days, and four of the special cars of the 
Commission are hatcheries in themselves and capable of taking 2,000,000 
to 4,000,000 eggs aboard at a time, the hatcheries can be quickly relieved 
in case of emergency. 

In 1897, 205,000,000 eggs were taken, from which 134,545,000 fry were 
hatched. In 1898, the total of shad fry hatched was 156,150,000, and 
in 1899 it was 210,493,000. 

In 1900, a permanent hatchery located on an arm of Albemarle Sound, 
near Edenton, North Carolina, was operated for the first time. This sta- 
tion is adjacent to one of the most important shad fishing-grounds in the 
country, and is intended to replenish the waters of Albemarle, Croatan, 
Roanoke, and Pamlico sounds, and their tributaries— the Pasquotank, 
Chowan, Roanoke, Pamlico, Neuse, and various minor rivers. This 
region annually yields upward of 8,500,000 pounds of shad, valued at 
about $350,000, and contributes the principal part of the shad found in 
the northern and eastern markets in winter and early spring. 

Potomac River.— The Potomac River, immediately adjacent to Fort 
Washington (12 miles below Washington, D. C), is probably more pro- 
ductive of ripe shad than any other area of the same size. This was 



Fish Manual. (To face page 128.) 



Plate 44. 




MANUAL OF FISH-CULTURE. 



129 



discovered as early as 1880, and a station was soon developed there 
with steam pumps, tanks, and hatching vessels. The seine operated at 
this point between 1887 and 1891 furnished 23 per cent of all eggs from 
the river. 

The following table, taken from the records of the station, shows the 
value of the spawning-grounds: 



Years. 



Number of 
eggs taken. 



j 20, 749, 000 

881. I 43,200,000 

882 21, 800, 000 

883 

884 

885 

886 

887 



24, 274, 000 
19, 000, 000 
22, 576, 000 
36, 362, 000 
59, 435, 000 

888 1 81,177,000 

889 ! 58, 233, 000 

890 j 35, 202, 000 



Years. 



Number of 
eggs taken. 



1891. 
1892. 
1893. 
1891. 
1895. 
1896. 
1897. 
1S98. 
1899. 
1900. 



980, 000 
440, 000 
423, 000 
393, 000 
065, 000 
788, 000 
707, 000 
724, 000 
283, 000 
904, 000 



In 1889 immense collections of eggs were made on certain days — 
8,368,000 on May 6 and 6,311,000 on May 7, and during seven days 
there was an average of over 5,000,000 per day. This was before and 
just after a freshet. 

To increase the supply of eggs, seine fishing has been attempted by 
the Commission on both the Susquehanna and Potomac, but the efforts 
were only partially successful and were finally abandoned. The exten- 
sion of egg-taking by seines can not be relied upon, especially as this 
method of fishing has been declining for many years, owing to its 
greater expense, and a corresponding growth has taken place in the 
gill-net fishery. It is often difficult to obtain the ripe eggs when the 
shad are taken in a seine on account of the great numbers of alewives 
taken at the same time. 

The following comparative table shows the shad-egg production from 
a Potomac River seine, together with the proportion of males, females, 
and spawning fish, and the number of eggs per fish: 



Year. 


Total 
number of 

eggs 
obtained. 


Total 

ripe 

fish. 


Total 

shad 

caught. 


Per cent 

of 

males. 


Per cent 

of 
females. 


Average 

number J p , 
of eggs Trine 
per fish ri ? e - 
spawned, j 


1887 


20, 956, 000 
22, 657, 000 
17, 738, 000 
10, 262, 000 
5, 276, 000 


652 
688 
612 
468 
228 


10, 348 

11,212 

6,217 

4,606 

3,138 


71.4 
69.2 
52.3 
54.3 
57.1 


28.6 
30.8 
47.7 
45.7 
42.9 


32,100 6.3 
32,900 6.1 

28,980 ! 9.8 
21,900 ! 10.1 
23, 140 ; 7. 2 


1888 


1889 


1890 


1891 



F. M. 



130 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 

Had all other fisheries furnished an equal percentage of eggs, the 
annual Potomac collections would have reached about 300,000,000. 
But while the Fort Washington seine, with a catch of 10,000 shad, gave 
20,000,000 eggs, and another, capturing 18,000, gave 17,000,000, a third 
catching 60,000 shad, gave only 1,000,000. 

Eggs taken by gill fishermen are usually superior to those from seines, 
and the gillers attach enough value to the market for eggs to save 
almost all within reach. At the commencement of the season many of 
them secure spawning-pans, which they keep in their boats, taking and 
fertilizing the eggs themselves, and when accidentally overlooked by 
the regular spawn-takers they sometimes row several miles to bring- 
in pans of eggs. In 1896 a giller who laid out his net with the special 
object of securing spawning shad, caught 3,300 fish and sold over 
6,000,000 eggs to the Commission. About 1,100 of his fish were roe 
shad; of the total, about 6 per cent were ripe; of the 1,100 roe, about 
20 per cent were ripe. 

The average catch of shad by the gillers who supply eggs is 1,600 to 
1,800 per season; but they do not all operate specially for the capture 
of spawning fish, though this work is profitable and gillers are fast 
turning attention to it. The Fort Washington gilling boats furnish on 
an average about 1,000,000 eggs each a season, those at White House 
400,000, Sandy Bar 350,000, Greenway 300,000, and Craney Island 
150,000, the average being about 500,000 per boat. 

Susquehanna River. — The shoal water in the neighborhood of Battery 
Station is an extensive and valuable spawning-ground. The station 
is conveniently situated on an island and the possibilities in egg- 
collecting appear to be almost unlimited. Hundreds of gill fishermen 
are engaged and large seines are operated within easy distance. In 
1886 the station was overrun with eggs; 170 universal hatching-jars 
and 58 cones would not contain them, large numbers being held in 
cylinders, buckets, and pans. In 1888 over 105,000,000 were taken, 
and in 1889 7,600,000 were obtained in one night. Both egg- collecting 
and hatching are carried on, and the establishment is complete in itself. 
There is no transfer of the eggs except for occasional car shipments, 
and the fry are carried to Havre de Grace in 10-gallon cans for railroad 
transfer to the places of deposit. 

Delaware River. — The steamer Fish Hawk has been employed in shad- 
hatching on this river nearly every season since 1887, the egg-collecting 
and other labor being performed by the crew. An interesting feature of 
the work is the large yield of eggs per fish. Eggs from this river have 
been saved regularly since 1887 from seines, but the available product 
among the gill fishermen has never been fully ascertained. 

The eggs collected by the Fish Hawk numbered 51,983,000 in 1899. 

The methods pursued at the different shad hatcheries are very similar. 
The following description applies particularly to the work on the Poto- 
mac River at Bryan Point. 



Fish Manual. (To face page 130.) 



Plate 45. 









MANUAL OP FISH-CULTURE. 131 

EGG-COLLECTING. 

Collecting eggs is the work of experienced watermen, who must be 
prepared to endure all kinds of weather in open boats. The boats are 
towed out to the fishing-grounds by steam-launches, where the spawn- 
takers visit the nets of the market fishermen, obtaining from them the 
spawning fish. After eggs have been obtained a ticket is dropped into 
each panful, with the date and the name of the fisherman, for entry on 
the books of the station. The price for eggs is always above the 
market price of the shad, and payment is made at the end of the season 
on the basis of 28,000 to the liquid quart, the price being $10 to $20 per 
1,000,000. On the Potomac 40 to 50 spawn-takers are employed at the 
station, besides 12 or 15 men who are engaged as hatching attendants, 
machinists, firemen, and cook^. 

The spawn-taker uses a 16-foot flat-bottomed bateau and is provided 
with a lantern, six small and four large spawn pans, and a dipper 
of suitable size. The pans are made of tin and are of two sizes, 
11-inch and 18-inch diameters, the latter with handles. The smaller are 
for receiving eggs on delivery from tbe fish, and the larger for carrying 
them. The pans are thoroughly washed each night after use and not 
allowed to become rusty or indented. The dippers are round-bottomed, 
hold nearly a quart, and have handles with open ends, with 5 inches of 
the free end wrapped with seine twine. To obtain eggs from a seine, 
double the above number of spawn vessels may be required. 

Spawn-taking tubs of indurated wood fiber have been introduced in 
Potomac River operations and found superior to tin, being without 
hoops or joints, non-corrosive, and non-conductors of heat. They have 
wood covers which fit inside the rims, and the tops fit tightly by means 
of a soft rubber joint: 4 inches of the central part of the cover is cut 
away to admit air. 

As the shad manipulated are sold and consumed in a fresh state, 
fishermen waste no time in transferring them to market boats, which 
are in waiting, and rapidity of execution is therefore required on the 
part of the spawn-taker, who must be alert and exact in his methods. 

In gill-net fishing there is usually ample time to assort the fish, 
which are taken into the boat one at a time, except when sudden 
squalls or exceptional captures force the premature hauling in of the 
net with the fish wound up in the meshes. Unskilled spawn-takers 
are liable to the mistake of stripping eggs without having the neces- 
sary milt to impregnate them, for several spawners may be taken over 
a period of ten or twenty minutes without the capture of a male fish. 
In such cases (of great frequency late in the season) the female fish 
must be placed conveniently, backs down, to prevent the eggs from 
running out, and the males may have to be obtained from other boats. 
When ripe shad are taken in seines, two or three large baskets should 
be in readiness to receive them. 

Sometimes the number of ripe fish will be sufficient to occupy all the 
attention that can be devoted to them; at other times the run of fish 



132 REPORT OF COMMISSIONER OP FISH AND FISHERIES. 

is greatly reduced by local conditions. Even when other conditions 
are satisfactory, if neither high nor low water occurs about sunset but 
few ripe fish are caught. The large seines land toward the last of the 
ebb tide, and gill net fishermen can do nothing except on the change of 
the tide — on slack water. The fish spawn at a certain time of day, 
and when taken at other hours are not in spawning condition. Thun- 
derstorms sometimes occur for days in succession about sunset, the 
very hour when most disastrous. 

A scarcity of male fish toward the end of the season often cuts short 
operations when eggs are plentiful. Unsuccessful attempts have 
been made to capture the males at such times by using gill nets with 
meshes smaller than those in the nets of market fishermen. Attempts 
have been made to pen the adults, but without success, as the fish 
become diseased and their eggs spoil within them. In gill nets the 
adult is entangled in the mesh and can not escape by struggling, and 
it therefore remains comparatively quiet. 

The quality of shad eggs is generally impaired where the fish are 
held for an hour or more in trap nets or seines. The eggs from fish 
taken in large seines are usually of bad quality, but those from short 
seines, which are landed quickly after the fish have been surrounded, 
are usually good; and those from trap nets, in which the fish have been 
held for some hours, are valueless. Eggs are rarely susceptible to fer- 
tilization longer than 20 minutes after the fish are taken from the water, 
though there are exceptions to this rule. On May 23, 1895, Potomac 
shad were stripped which had been out of the water about 1^ hours; 
they were kept separate, and at the end of 48 hours produced 100,000 
eggs, which yielded 98,000 fry. 

The shad dies very quickly after capture and is immediately respon- 
sive to electrical storms, the catch of seines and nets of all kinds falling 
off promptly when a thunderstorm develops. Eveu in seines already 
laid out in the water, with lead line on the bottom, there is an appre- 
ciable decrease in such event. On the Delaware River, May 29, 1887, 
nearly ;j0 per cent of the shad eggs on board the steamer Fish Hatch 
perished during an electrical storm which continued from 6 p. in. to 
midnight. There were 4,481,000 eggs with embryos well formed, and 
without perceptible change in water temperature 1,918,000 were killed, 
many turning white by 8 p. m. 

Heavy freshets cause an abrupt suspension of fishing, but the effect 
of a single freshet is usually temporary. The shad which have gone 
above are backed down before the muddy water, but reappear upon its 
outward passage. An occurrence of this kind will effect a great 
increase in egg receipts if the water temperature before muddy water 
comes is suitable. The shad that were scattered above being thrown 
back in a body, reascend in a body. 

A season of clear water is undesirable both for fishermen and hatching 
work, as the fish see the nets and avoid them, gill nets being put out 
only on the night tide and half the fishing being thus lost. The water 



MANUAL OF FISH-CULTURE. 133 

should be discolored enough to prevent the fish from seeing the nets, 
but not thick, say from 10 to 20.* An occasional freshet reduces the 
temperature and prolongs the season ; however, with an equal number 
of fish in the rivers, clear water is probably more advantageous for 
natural increase, as a large proportion of naturally deposited eggs must 
perish from suffocation under the mud in seasons of freshet. 

THE WEATHER AND SPAWN. 

The development of eggs within the ovaries is hastened by heat and 
retarded by cold. In a warm season fish ready to spawn are more 
numerous early in the season than in a cold one, and the period for 
obtaining them is apt to close earlier. The eggs, not only after they 
are deposited and impregnated, but before they leave the body of the fish, 
are affected by the temperature of the water, often being "blighted" 
or "rotten ripe." This phenomenon was observed as far back as 1873. 
It occurs on the water reaching 80° to 81°, or with a rapid rise. On 
the other hand, a sudden fall in temperature has been observed to 
arrest natural spawning, produce blighted eggs, and to destroy those 
in the hatching vessels. Continued low temperature is also disastrous 
to fishing. 

An abnormally inferior quality of the Potomac Eiver eggs was noticed 
during the full period of operations in 1896. The bulk of the run of shad 
made their appearance on a rapidly ascending temperature, and the 
eggs were injured within the parent fish, more than half perishing 
before conversion into fry. The rise in temperature was greater than 
had been recorded in the eleven years preceding. The run of shad 
increased proportionately, the catch at'one seine increasing from 100 
to 800 in 24 hours. A snowstorm on April 7— morning air temperature 
35° F. and mean air temperature 46° — was followed by heavy frost on 
April 9, the morning air temperature on the last-named date being 34°. 
The river water on April 10 was 46°, rising to 48° on April 12 and to 
71° in the afternoon of April 21, thus gaining 25° in 10 days. After 
April 21 the catch of shad fell off to such an extent that fishing was 
no longer profitable. 

The water of the Potomac early in March is usually of a temperature 
of 36° to 40°, rising to 52° to 58° about the middle of April, when the 
spawning period begins, and at the end of May, the close of the period, 
it averages from 65° to 70°. 

STRIPPING AND FERTILIZING THE EGGS. 

In stripping the eggs the shad is lifted with the right hand and 
caught above the tail with the left. All slime and loose scales are 
removed by going over the fish two or three times in quick succession 
with the right hand. The head is carried to the left side under the 

*Tke condition that permits the discernment of objects at a distance of 10 to 20 
inches beneath the water surface, the method of registration employed by the Wash- 
ington (D. C.) aqueduct office. 



134 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 

arm and there retained by the arm, the tail being bent slightly upward 
with the left hand. When the fish is properly adjusted its head is 
nearly concealed. The fish is held firmly over a moist pan, and with 
a moderate downward pressure of the right hand the eggs will flow 
freely if mature. The strokes are continued until there are signs of 
blood, which usually accompany the last eggs. The fingers should not 
touch the gills of the fish, as laceration of these organs causes a flow of 
blood injurious to the eggs. Two fish may be stripped into each pan. 

As soon as the spawn is all obtained, the shad is discarded, it being 
impossible to preserve the life of such a delicate fish, even with tho 
utmost care. But though it has slight tenacity of life when taken from 
the water, the shad is a very muscular fish, and if not firmly held it will 
flounder and splash in the pan of eggs and probably throw a large 
proportion out and damage some of those that remain. 

The first half teaspoonful of eggs should be pressed out into the 
palm of the left hand and inspected. Skilled operatives can usually 
discern ripeness by general outward appearance. A slow and yet 
almost positive test consists in running some of the eggs into water, 
when, if dead, they will have the appearance of boiled rice. But bad 
eggs are sometimes beyond the detection of the most skilled fish- 
culturists. If the eggs are white, opaque, or of milky appearance, the 
fish is put aside. Immature eggs are white, small, and adhering in 
clots; or they may be transparent and yet unyielding to pressure. 
The former are valueless, while the latter can sometimes be utilized by 
putting the fish aside to soften. Both ripe and green eggs sometimes 
occur in the same fish, but only expert operatives can hope to take the 
one and leave the other. If eggs are mature, but little pressure is 
necessary to start them, and if not, they are only injured by squeezing, 
and will either not flow at all, or will come away with difficulty in clotted 
masses and generally with a little blood. After the spawn is taken 
away, the fish has a soft and flaccid appearance about the abdomen, 
which after natural spawning becomes contracted and drawn up, taper- 
ing slenderly toward the tail. 

Eggs of the best grade may be impaired by intermixture of overripe 
or green ones, lumps of milt, tissues of the sperm sac, or fish scales. The 
overripe and unfertilized ones can be discarded, and a tiny net, an inch 
square, or a straw or twig, maybe used in removing foreign substances. 
The spawn-taker should clean the eggs before delivering them at the 
hatchery, and no subsequent care can compensate for his neglect. 
Experienced men rarely bring in bad eggs, unless as a result of vari- 
able and unfavorable weather conditions. 

To obtain the milt the spawn-taker catches the fish by the back, 
taking hold of the under side with the right hand. Without relaxing 
pressure at any point the milt is forced out with the thumb and fore- 
finger. Good milt is so thin that it flows in a steady stream, and from 
some fish it can be ejected widely over the surface of the eggs, but in 



MANUAL OF FISH-CULTURE. 135 

fish which have been dead some minutes the milt is lumpy and flows 
only in drops. A teaspoonful will fertilize 40,000 to 75,000. After the 
milt has been applied, from half a pint to a pint of water from the river 
is added and the pan given a slow rotary motion, continued till the milt 
is thoroughly mixed, when a milky appearance is imparted to the water. 
When the river water is turbid, clear water must be obtained before work 
is commenced. 

In gill-net boats eggs thus treated will expand without further imme- 
diate attention, for there is sufficient motion from the boat to prevent 
clotting; shad eggs do not "cement" when the milt is applied to them, 
as in the case with salmon and trout eggs ; but they adhere, and if left 
perfectly quiet, as on shore, a large proportion will be lifeless. Those 
comprising the lower strata may either lack sufficient expansive power 
to absorb water under weight of the others, or in the suction of each 
separate egg, in the natural tendency to absorb water, they may have 
a cupping effect upon one another, thus preventing water contact. 
Whatever the cause, they stick together in one mass, and only those 
of the upper layers receive sufficient water; the others remain under- 
sized and die. Large quantities of eggs must be separated, either by 
agitating the water already in the pan or by the addition of more. 

In one minute after thorough mixing the milt can be washed off with 
safety, but usually several pans are to be looked after, when the milt 
may be allowed to remain 5, 10, or even 15 minutes. After the last 
pan of eggs has been fertilized, they are rinsed, beginning with those 
first taken, by pouring in a quart of water, placing the edge of the 
dipper so that the stream is directed between the eggs and the sides 
of the pan, as the eggs may be injured if the water is poured directly 
upon them. Then the pan is oscillated, the water being drained over 
the edge slowly, and, the operation being repeated, the third quart of 
water is left upon the eggs. The eggs must be well stirred with the 
inflowing water. 

There need be no fear of applying too much milt. The amount 
obtained from one fish may be ample for the eggs from two, but it is 
always better to employ two males. Eggs may look promising for two 
or three hours, yet never expand to full size or produce fish. They lie 
at the bottom, and underneath any good ones which may be in the 
pan; they stick to the fingers, while the good ones will not, nor can 
they be successfully removed from hatching-jars until after several 
days' decomposition. By using two pans, good eggs may be separated 
from bad by pouring, but the process is slow and there is usually no 
time in the hatcheries for such operations. 

Good eggs are very transparent and so soft and light that they are 
not apparent to the touch when the fingers are moved among them. 
When the temperature is about 70°, no change is observed for about 
12 or 13 minutes after the milt is added, but about this time a careful 
movement of the fingers in the pan discloses their presence, and in a 



136 KEPORT OF COMxMISSIONER OF FISH AND FISHERIES. 

little more than 20 minutes from the time the milt is applied they feel 
like shot against the fingers, and to an experienced eye are observed 
to increase slightly in size; when a day old, they will not break if 
dropped to the floor. In transferring to other vessels, the rim of the 
smaller pan should be gently immersed beneath the water surface in the 
larger one, and the pouring take place gradually. To prevent splashing, 
in boats, a small pan should be put on the water surface of the larger 
pan. Sudden jars must be avoided, all foreign substances excluded, and 
the pans be free from grease and salt. After the application of milt 
they expand to full size in 20 to 60 minutes, depending partly on tem- 
perature, and at this stage they may be doubled up in the larger pans, the 
question of safety in moving them being determined by their hardness. 




Pans used in cleaning eggs. 

When eggs are received at the station, in order to thoroughly remove 
all impurities they are passed through netting, and for this purpose, 
two 18-inch flared tin pans with handles, one pan fitting within the 
other, are employed; 2 inches of ttie bottom part of the inner pan are 
evenly cut off and replaced with quarter-inch (bar) twine netting. The 
lower pan is filled with water to a point just above the netting, and 
then several quarts of eggs are gently poured in. when they drop through 
the meshes, leaving the fish scales, etc., behind. Thus they are also 
given a change of water, which should be clean and fresh and of about 
the same temperature as that in the hatchery and river. 

If the eggs have absorbed sufficient water in the spawn-pan, they 
swell and adhere to each other, forming a compact mass, and are ready 
to be transferred to the hatching-jars, but if they are not sufficiently 
expanded or "water-hardened," they must remain in the pans, from 30 
to 60 minutes being required for their full expansion. 



MANUAL OF FISH-CULTURE. 



137 



HATCHERIES AND EQUIPMENT. 

The building for a shad-hatchery maybe of a tenrporary character, as 
it is used only about two months each year, but ample light, space, 
ventilation, and arrangements for moderate heating are necessary. The 
steam boiler and pumps should be in a separate structure. 

In exceptional cases, as at Central Station, in Washington, river 
water from city pipes can be utilized. If the water supply is taken 
directly from the river the suction should be put below low-water mark, 
and the end provided with a strainer and kept off the bottom to avoid 
sediment. The water should be supplied from an open tank, not by a 
force-pump, but if it is taken from municipal pipes a regulator may be 
employed. A fall of 16 feet is desirable, or 8 pounds pressure per square 
inch at the top of the hatching-jars. The amount required is 2 quarts" 
per minute to each jar. 







Plan. 




A 




r— i- 

j | 

r~1 

■ 




l'"Tj 




I 


Tl 

': i 

Lj—i 








! 


1 INCH rALL 


(g) 






] 
i 



^ reet 



Upper figure showing view froni 
above. 

Lower left-hand figure: End view 
showing hatching-jar in position. 

Lower right-hand figure: Cross- 
section showing the drain-pipe and 
trough in center of table. 




Section A-B 




Shad-hatch in £ tahle. 



The jars are arranged on tables, as shown in the cut. « From a large 
iron pipe, branch piping of 1£ to 2 inches diameter is run over each 
table, where ^-inch brass pet-cocks are inserted 6 inches apart. The 
jars are connected with the supply-pipes by half inch rubber tubing. 
Tight drains are required to carry away the waste water. Collector- 
tanks for fry are rectangular and may be of glass or wood, the former 
possibly preferred. 



138 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 

The overflow from the collectors is guarded by a wire- gauze or cheese- 
cloth strainer. A safe and interchangeable device consists of a stout 
wire frame, over which a cheese-cloth bag is drawn and tied. A 
finch rubber hose is attached to the opening in the frame. The 
strainer is put inside among the fry, and the outflow in an overflow cup. 
The overflow cup is set at the proper height to control the water level 
in the collector-tank. Long-handled nets of ^-inch mesh are required 
to remove egg lumps or other matter from the jars. 



THE AUTOMATIC HATCHING-JAR. 

The United States Fish Commission, in the development of its 
work, had presented to it the necessity of dealing with the eggs of the 

whitefish and the shad upon a 
scale unprecedented in the his- 
tory of fish-culture. Millions 
were to be handled instead of 
thousands, and the removal of 
dead eggs by hand picking was 
no longer to be considered. 
After successive experiments 
the McDonald automatic hatch- 
ing-jar was devised, and it is 
now generally employed. 

The most meritorious feature 
of this apparatus is that it 
prevents the development of 
the saprolegnious fungus, which 
caused so great a mortality in 
some other forms of hatching 
contrivances in which all the ova 
were not in continual movement. 
The very gradual, gentle, and 
continual rolling movement of 
the ova upon each other in the 
jar apparently prevents the 
spores of the fungus from ad- 




Automatic shad-hatching jar. 



hering. The cleanliness of the apparatus is also advantageous, and as 
the material of which it is made is glass, the progress of development 
can be watched satisfactorily from the outside of the jar with a hand 
glass or pocket lens of moderate power. 

The jar is a cylindrical glass vessel, of about 7 quarts' capacity, 
with hemispherical bottom, supported upon three glass legs. The top 
is made with threads to receive a screw cap. It is closed by a metallic 
disk perforated with two holes five eighths inch in diameter — one in 
the center admits the glass tube that introduces the water into the 
jar, the other, equally distant from the central hole and the edge of 



MANUAL OF FISH-CULTURE. 



139 



the metal plate, admits the glass tube which carries off the waste 
water. The central tube is connected by half-iuch rubber tubing with 
the pet-cock, which regulates the supply of water. A groove in the 
inner surface of the metallic plate carries a rubber collar, and when 
the plate is in place the tightening of the metallic screw-cap seals the 
opening hermetically. Both the iulet and outlet tubes pass through 
stuffing-boxes provided with gum-washers and binding-screws. The 
central or feed tube is provided with stuffing-boxes, one on the top of 
the disk and one on the bottom, the better to hold it to a true center. 
The outlet tube is provided with only one stuffing-box, and the binding- 
ring is beveled. 

In preparing the jar for work the side tube is fitted first. The glass 
tube should be wet, the gum-washer slipped on the tube about an inch 
from the end and introduced into the opening. Holding the tube per- 
pendicularly to the face of the plate, press fairly on the tube, and the 
washer, rolling on itself, will fall into the seat provided for it. Screw 
on the binding- 
ring, and test by 
seeing that the 
tube slides freely 
back and forth in 
the stuffing-box; 
if not, it should 
be refitted with a 
heavier or lighter 
washer, as maybe 
required. Glass 
tubes can not be 
procured of abso- 
lute uniformity in Egg Funnel, 
size. Water is the only lubricant that should be used about the jar 
fittings. 

The jar, after being washed clean, is filled with fresh water. A 
shallow tin funnel with a perforated rim is inserted, so that the water 
will stand as high in the funnel-throat as possible, and the eggs are 
poured in by dipperfuls, or when taken from transportation trays are 
washed in by a jet of water. Care is used to have the eggs fall but a 
short distance, and no fish scales or other foreign matter should enter 
the jar with them, as the presence of anything but water and eggs ren- 
ders a proper motion of the mass impossible, and usually results in the 
loss of a large proportion of the eggs. The requisite number of eggs, 
80,000 to 100,000, being in the jar, it is put in position and closed, 
care being taken that both the inlet and outlet tubes slide freely in 
their stuffing-boxes. If the tubes become gummed, let water trickie 
down around the binding-screws. To close the jar, turn on the water, 
place the feed-tube in the jar, turning off the water immediately after 
the feed -tube has passed beneath the surface of the water in the jar, 




140 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 

thus expelling all the air from the feed -tube; otherwise it would rise 
in bubbles, throwing a portion of the eggs out through the outlet-tube. 

With a proper quantity of semi-buoyant eggs in the jar and the 
water turned on and regulated, the movement of the current estab- 
lishes a regular boiling motion in the mass of eggs, which brings each 
(n succession to the surface. This motion may be regulated without 
altering the quantity of water. By loosening the upper binding-screw 
of the central stuffing-box, and pushing the feed-tube down until it 
almost comes in contact with the bottom of the jar, the motion of the 
eggs is increased. If the jar is working properly, the dead eggs when 
brought to the surface remain on top, forming a distinct layer, and by 
pushing down the outlet tube a suitable distance they are lifted up 
by the escaping current and taken out. 

When the water is turned on for tbe first time the jar should be 
watched closely until a regular motion has been established. When 
eggs have stood 15 or 20 minutes in the jar before the water is turned 
on they do not readily yield to the boiling motion, but tend to rise in a 
solid mass to the top of the jar. By quickly starting and stopping the 
current the mass is readily disintegrated. The degree or intensity of 
motion of the eggs varies not only with their age and condition, but also 
with the condition of the water. If the water is muddy, the motion 
should be rapid enough to prevent mud settling either on the eggs or in 
the bottom of the jar. Ordinarily the best motion is that which readily 
brings the dead eggs to the surface. After the hatching has progressed 
far enough to dispose of a portion of the eggs there is less resistance to 
the current, and it should be reduced by shutting off part of the supply 
or by slightly lifting the central tube. If the motion is not reduced 
from time to time as the hatching progresses, shells will be carried over 
into the receiving-tank with the fish and, being very light, will be drawn 
against the outlet screen, causing an overflow. The motion should be 
so gentle at the time of the greatest hatching as barely to induce the fish 
to swim out of the jar and leave their cast-off shells behind. 

Very healthy eggs, exposed to bright direct sunshine, hatch so rapidly 
that the combined effort of the swarming mass of young fish will 
establish sufficient current to draw some shells over into the receiving- 
tank. This may be modified by placing a screen between the jar and 
the light. The shells under normal conditions remain and form a 
cloud-like layer above the mass of working eggs. As they accumulate 
they should be removed by shoving down the outlet- tube until they. are 
drawn up with the escaping water. A good plan is to draw several 
jars in succession into a large pan, whence any fish coming over with 
the shells may be ladled into the receiving- tank. 

A remnant of eggs may be long in hatching, and they should be 
poured into a large, clean, bright pan and exposed to bright sunlight, 
when they will hatch in five or ten minutes. 

If the connection of the jar must be broken, it is essential that the 
rubber feed-tube does not drop down and siphon the eggs from the jar. 



Fish Manual. (To face page 140.) 



Plate 46. 



SSB 







MANUAL OF FISH-CULTURE. 141 

In reconnecting, the air may be expelled with the metal top screwed 
down in position. To effect this, draw both glass tubes up to the top of 
the jar and turn on a full head of water, when the air will be forced out 
in bubbles above the eggs, the bubbles escaping through the outlet 
tube. The central tube is now restored to its former position. The 
automatic action permits entire separation of bad from good eggs, 
though some days may be required to accomplish the full result. The 
dead become lighter from gases arising from decomposition. A net, 
small enough to easily enter the mouth of the jar and fixed to a handle 
several inches longer than the jar, is convenient for removing particles 
of foreign matter. 

Shad eggs are semi-buoyant, and those which will not rise commence 
lumping on the third or fourth day. The usual period of hatching is 
from G to 10 days, sometimes longer, according to temperature of water, 
but with high temperature they will hatch in 3 days. Fry hatched in 
less than 5 days are usually, though not always, weak. In general, the 
period of incubation varies inversely with the prevailing temperature, 
but continuous dark and cloudy days will retard and strong light will 
accelerate development under precisely the same conditions of water 
temperature, and other circumstances not well understood may also 
have their influence. 

Fry when hatched are about 0.37 inch long. They have been meas- 
ured at intervals of from 5 to 15 days, from late in May to the middle 
of October. Toward the middle of August the rate in growth dimin- 
ishes. When days old i hey are about 0.(32 inch long. Fry 0.5 inch 
long July 20th were 0.75 inch long 8 days later; on August 14th, 2 to 
2.25 inches; September 20th, 3 to 4 inches; October 1st, 4 to 4£ inches; 
November 4th, 5 to 7 inches. Some years they grow faster than others, 
and in some streams more rapidly than in others. From the State fish- 
ponds at Ealeigh, North Carolina, 33 were removed in November, 1884, 
which measured 8 to 9 inches. Their usual size in the Potomac in the 
fall is 3 to 4 inches. 

MEASURING THE EGGS AND FRY. 

To estimate the number of eggs and of the young fry was for years 
rather a difficult matter to accomplish satisfactorily. The standard 
made use of at the outset was undoubtedly much too high. The scale 
most used at present is a light square, made of wood, the longer leg 
being 15 inches and the shorter 7£ inches long. The material is £ inch 
wide and ^ inch thick. The graduations are on the longer leg, aud 
read from the lower end upward. The first line is at a height corre- 
sponding to the level attained in the jar by a measured half- pint of 
water, and the succeeding lines are determined by the introduction of 
additional half-pints of water. When the scale is being constructed, 
the central glass tube is stopped at the lower end that it may displace 
an amoun-t of water equal to the amount of eggs it will displace in 



142 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



practice. Each line on the measuring stick registers 7,000 shad eggs. 
The number of eggs in a liquid pint is established by actual count. 
Those which are very young or have been lately on trays are not of 
normal size and not qualified for measurement. The eggs are at rest 
when measured. 

The jar contents are determined by placing the short leg of the 
measuring-stick over the top, with the other pointing downward and 
touching the side of the jar. The uumber is indicated on the scale at 
the point opposite the surface of the bulk of the eggs. Scarcely any 
semi-buoyant eggs die, under proper conditions, after hatching out has 
commenced, and a close approximation to the number of fry may be 
obtained from the last measurement, which is 
made after the careful removal of all dead eggs 
and the bursting forth of the first young. 

FEEDING AND REARING. 

The young shad swims vigorously, by rapid 
and continuous vibration of the tail, from the 
moment it leaves the egg. It is colorless, trans- 
parent, and gelatinous. Several hundred in a 
dipper are scarcely discernible. It has a rela- 
tively large yolk-sac, but supports it with ease 
during the first four or five days after hatching, 
the small quantity remaining after this time not 
being visible externally, although found in shad 
fry 14 to 16 days old. Minute conical teeth make 
their appearance on the lower jaws and in the 
pharynx about the second or third day after 
hatching. The jaws at three months are armed 
with teeth slightly curved. 

Young shad feed on other minute organisms, 

such as exceedingly small crustaceans. Food 

lllfe 1 i hm has never been observed in the alimentary canal 

vj|| P^^^/ until ten or twelve days after the young fish had 

'^i_P^^ "vO.j left the egg. At about the middle of the second 

Application of a measur- week considerable may be seen, but the intestine 

ingscaletoa jar of shad j s then not often very densely packed. At the 

e §'S 8 - a ,ge of three weeks an abundance of food is 

found. They have been known at this early age to eat their own kind, 

and later the young carp and salmon. When cold, raw winds drive 

the crustaceans into deeper water, the young shad follow them, and 

in aquaria they take Crustacea freely. In salt-water aquaria they may 

be fed upon chopped oysters and canned herring-roe. 

Experiments with young shad have been carried on for several years 
at Central Station in salt-water aquaria. On one occasion about 250 
were received in October, at which time they were about five months 
old. They were put in brackish water, specific gravity 1.005, which 




MANUAL OF FISH-CULTURE. 143 

was added to from day to day for nearly a week, when it was brought 
up to 1.018, or the same specific gravity as the water used in the marine 
aquaria. At the time these were placed in the brackish water others 
were put into fresh -water aquaria, but the latter died within three 
days. Those in salt water began in two or three days to take food, 
consisting of chopped 03'sters, clams, and beef, the preference being 
for oysters. At first they would take food only when it was sinking, 
later they began taking it off plants where it had lodged, and finally 
from the bottom. Nearly all remained healthy, plump, and active for 
six months, some living until about midsummer. 

For ten years past two or three million shad fry have been reared 
annually at the Fish Ponds, Washington, D. 0. A 6-acre pond is used, 
the water supply being taken from the city water- works. The depth 
varies from 2 to 3 feet, and throughout the whole extent there is a dense 
growth of water-plants, among which crustacean food multiplies — new 
supplies being brought in from the water-pipes. Fingerling shad are 
so tender that the numbers annually liberated can not be ascertained; 
they can not withstand the handling consequent upon counting them, 
not even undergoing transfer in dippers of water, and their scales drop 
off on being touched; consequently at high tide they are liberated into 
the Potomac through a sluice-gate with an outlet pipe about 2 feet in 
diameter. They require some days to make their escape. By conserva 
tive estimate 50 to 60 per cent are held safely until about October. 

Rearing has been experimentally tested at Wythevilie and Neosho 
with good results. At JSTeosho on the 3d of June, 1892, 700,000 fry were 
received from Gloucester, 1ST. J.; their growth was satisfactory. In 
preparing for their release the hatchery branch was cleared of shoals, 
drifts, and aquatic plants for three-quarters of a mile, and early in 
November, when the branch was swollen with rain water, 200,000 
6-months-old fish were allowed to pass through open gites ; they were 
some hours in escaping, in a continuous silvery mass. These were the 
first fingerling shad planted in waters tributary to the Gulf of Mexico. 

TRANSPORTATION. 

Good, healthy fry will pass from the jar to the collector-tank as fast 
as hatched, and unless too thick will not lie on the bottom of the tank, 
although they sometimes crowd on the side nearest the strongest rays 
of light. As many as 500,000 to 800,000 are collected in each tank. 
In transporting, they must be kept in vessels with smooth surfaces, 
preferably tin-lined cans. Zinc vessels are destructive, and galvanized 
cans are not recommended. 

About 2,000 to 3,000 fry are put to a gallon of water, which must be 
pure enough for ordinary drinking purposes and well aerated. The 
water in the cans must be kept at 58° to 65°, though in rivers and 
ponds the fry endure a temperature of 90° F. 

As early as 1874, experiments were carried on to retard the develop 
ment of eggs, in order to provide a longer period between the delivery 



144 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 

of the eggs from the parent fish and the absorption of the yolk-sac. 
Eggs, when transported, were placed on trays and put under melting 
ice, and later experiments have been conducted inside refrigerator 
boxes. 

Pathological changes or deformities are induced in the embryos when 
subjected to too low a temperature or when held long enough on damp 
iiannel trays (ordinary air temperatures) to hatch. 

It would appear that 55° to 53° is the lowest temperature in which 
ova will safely undergo their normal development and 9 days is the 
longest period of incubation attainable at that temperature — time suffi- 
cient, when added to the several days required for the young to absorb 
the yolk-sac, to ship them to Europe, though efforts in this direction 
have thus far failed. One drawback is the rapid development of fun- 
gus, which grows over the eggs, penetrates the membranes, and kills 
the ova. 

The eggs are shipped in crates of 20 shallow trays, the frames of the 
latter being of wood with bottoms of wire mesh about 8 to the linear 
inch. Wood and wire are painted with asphaltum. Each tray is 
covered with cheese-cloth, somewhat overlapping the edges, the cloths 
being hemmed, to avoid ravelings. There are two frames of wood, 
connected with leather straps; one the base and the other the cover for 
the stack of trays. The trays, after being filled with eggs, are wrapped 
in a long, cotton-goods apron and strapped together. There is an iron 
handle on the top frame, and the lowermost tray is put down empty 
with the wire surface upward. Then follow the trays containing eggs, 
the uppermost one being put on empty with the wire surface up. The 
top and bottom trays are merely to protect the others. 

The greater part of the water above the eggs is poured off from the 
jars and the remainder poured into tin pans along with the eggs. 
The cloths, after soaking in water, are arranged one by one on the 
trays and tucked closely into the four corners. The trays are stacked 
up and eggs poured evenly over the surface of the top one with a 
large dipper, and each tray, when filled, is put on the crate base. The 
surplus water drains away to the manipulating table. Tray cloths 
which are made of material too closely woven to let the water through 
are unsuitable. 

The eggs are bailed up in dippers with the water that they are in, and 
usually spread two layers deep, but may be put on more thickly. When 
eighteen trays are filled they are wrapped in the outer cloth, previously 
soaked in water, and tightly buckled together. The crate covers and 
tray cloths are boiled in water each time after use. 

Each tray — 14 by 19 inches area, with two layers of eggs — holds 
about 20,000 eggs, the contents of a full crate representing from 300,000 
to 400,000 eggs. While in transit the crates are sprinkled with river 
water on the sides at least once an hour, and kept in the shade, away 
from the cooling influence of the wind, to preserve even temperature. 



MANUAL OF FISH-CULTURE. 145 

TRANSPLANTING. 

The propagation of shad is mainly carried on to maintain or increase 
the supply in rivers where the species is native, but this fish has also 
been planted in waters in which it was either unknown or found in 
small quantities. Large numbers of fry have been liberated in tribu- 
taries of the Gulf of Mexico, but without marked results. Between 
1873 and 1892 several million fry were experimentally placed in Great 
Salt Lake, Utah Lake, and Bear Lake, Utah; and from 1884 to 1886, 
3,000,000 fry were liberated in the Colorado River at the Needles, in 
Arizona, but these experiments were unsuccessful. 

Remarkable success has, however, attended the stocking of the 
waters of the Pacific coast. In 1871, 12,000 shad fry from the Hudson 
River were liberated in the Sacramento River by the California Fish 
Commission, and in '873 the United States Commission made a second 
deposit of 35,000. Subsequent plants in the Sacramento, aggregating 
609,000, were made by the United States Commission from 1876 to 
1880. From these small colonies, amounting to less than 1 per cent of 
the number now annually planted in the Atlantic Slope rivers, the shad 
have multiplied and distributed themselves along nearly 3,000 miles 
of the coast from southern California to southeastern Alaska. They 
reached Rogue River, Oregon, in 1882. In the Columbia a few were 
taken as early as 1876 or 1877. About 1881 or 1882 they were on the 
coast of Washington, reaching Puget Sound in 1882. They appeared 
in the Fraser River, British Columbia, in 1891; in the Stikine River, 
near Wrangell Island, Alaska, the same year, and are now found along 
the entire coast from Los Angeles County, Cal., to Chilkat, Alaska, 
covering 22 degrees of latitude. Their distribution, from the standpoint 
of commercial importance, is from Monterey Bay to Puget Sound, 

On the northern part of the coast the firsc shad fry were introduced in 
1885, the number being 60,000. Of these, 50,000 were put in the Willa- 
mette River and 10,000 in the Snake River. The following year 850,000 
were introduced into the Columbia River. 

The shad is now one of the most abundant fishes of California. As 
a result of the liberation of the first two consignments, adult shad were 
caught in 1874, and by 1876 this fish had become numerous. In 1880 
specimens of all sizes were taken in the Sacramento River and Monterey 
Bay, and it was evideDt that the shad had begun to multiply, its increase 
up to 1883 being marvelous. It is most numerous on the west coast in 
San Francisco Bay and its tributaries, where, contrary to its habits in 
Atlantic waters, it is found throughout the year. It is not common 
above Sacramento, owing to the low water temperature. In the Col- 
umbia it is regularly found as far as the Cascades, about 150 miles above 
the mouth of the river. 

F. M. 10 



fish Manual, (To face page 165.) 



PLATE 51 



■:$k 







THE PIKE PERCH OR WALL-EYED PIKE. 



DESCRIPTION OF THE SPECIES. 

The pike perch (Stizostedion vitreum) is the largest member of the 
perch family inhabiting American waters. The body is fusiform; its 
depth being contained about 4J : times in length. The head is long, 
pointed, and a little more than one-fourth the body length. The large 
mouth is provided with bands of villiform teeth, in addition to which 
there are long, formidable canine teeth on the jaws and roof of mouth. 
The eye is contained 4i to 5 times in head. Serrations exist on the 
preopercular bone, and several spines on the preopercle. The high 
dorsal fins are well separated, and contain from 12 to 16 spines and 19 
to 21 soft rays. Tbe number of rows of scales in a lateral series is 
from 110 to 132, with about 10 rows above and 25 rows below the lateral 
line. The general body color varies from light yellowish to dark blue, 
with indistinct lines and mottlings, the under parts being white or pink. 
A large black spot involves the membrane of the last two or three 
dorsal spines, the fin being otherwise uearly plain; the second dorsal 
and the caudal are mottled with yellow and olive; the pectoral is dusky 
at its base, and the anal and ventral s are pinkish. 

Three rather well-defined color varieties of the pike perch may be 
recognized, dependent on age and environmental conditions. These are 
the gray, yellow, and blue. The gray variety attains the largest size, 
40 pounds being the maximum and 10 to 20 pounds being common. The 
yellow form reaches a weight of 20 pounds, and is often taken weighing 
5 to 10 pounds. It has the widest, range and is the most numerous. 
The blue pike occasionally may reach a weight of 5 pounds, but averages 
under 1 pound. The gray and yellow varieties are usually found in the 
larger streams, and in the Great Lakes seek water 10 to 40 feet deep, 
while the blue variety seems to prefer water 30 to 75 feet deep. 

The pike perch in that part of Lake Erie adjacent to the islands 
of the western end are almost or entirely free from yellow, being a dark 
gray, almost black, on the back, shading on the sides to lighter grays, 
while the lower third and belly are silvery white; the body is less com- 
pressed and tapers less toward the tail than the yellow variety. In 
Sandusky Bay there is a uniformly yellow variety, of a fusiform shape. 
Although Sandusky is connected with the lake by a deep channel over 
a mile wide, it is reported that the yellow fish do not leave the bay and 
the gray fish rarely enter except during the spring, when small numbers 
resort to it to spawn. 

From the sauger or sand pike (8. canadense), the wall-eyed pike is dis- 
tinguished by its fewer pyloric coeca (3 instead of 5 to 7), fewer dorsal 

165 



166 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 

rays, larger size, presence of black blotch, on second dorsal, absence of 
similar blotch at base of pectorals, and some minor characters. 

Various names are given to the pike perch in different parts of its 
habitat, and two or more names in some localities. Wall-eyed pike 
is the most widely used designation Pike and pickerel are employed 
in the Great Lakes. As both of these names are also borne by the 
members of the genus Lucius, much confusion has arisen. In the Sus- 
quehanna and Delaware rivers and along the Ohio and its tributaries 
the fish is very inappropriately known as salmon. Dory or dore is a 
Canadian designation. Other names in use on the Great Lakes and 
elsewhere are yellow pike, blue pike, glass-eye, white-eye, and jack 
salmon. In order to avoid confusion and to indicate the family rela- 
tionship, the U. S. Fish Commission has recommended the name pike 
perch, the fish being a perch of pike-like appearance and habits. This 
name corresponds with the generic term Lucioperca, applied to a similar 
European species. The sauger, however, is entitled to bear the same 
name, although its usual designation is distinctive. 

GEOGRAPHICAL DISTRIBUTION. 

The pike perch prefers clear water, with rock, gravel, sand, or hard- 
clay bottom. The center of its abundance is Lake Erie, but it is among 
the most widely distributed of our fresh- water fishes, its range extend- 
ing along the Atlantic seaboard from New Brunswick, New Hampshire, 
Massachusetts, and Connecticut as far south as North Carolina; thence 
to the northern portions of Alabama, Georgia, Mississippi, and Arkan- 
sas on the south, with Kansas, Nebraska, the Dakotas, and Assiniboia 
its western limit and the Hudson Bay system its northern boundary. 
Over the greater part of this vast area it is fairly abundant, and in all 
of the waters of the Great Lakes region, the Mississippi basin, and the 
southern portion, at least, of the Hudson Bay system it is commercially 
important. In New Hampshire, Connecticut, New Jersey, and eastern 
Pennsylvania it is not indigenous. Its adaptability to suitable new 
waters is shown by its acclimatization in the Susquehanna and Dela- 
ware in Pennsylvania, in many small lakes in Michigan, and in the 
streams and lakes of Nebraska, where it has rapidly multiplied and is a 
great favorite with anglers and epicures. 

The range of the sauger is less extensive than that of the wall-eyed 
pike. It embraces the Great Lakes region, west to the Upper Missouri, 
and south to Arkansas and Tennessee. 

ECONOMIC VALUE, FOOD AND GAME QUALITIES. 

The pike perch is one of the most valuable fresh-water fishes. In 
Lake Erie alone the annual catch is now upward of 0,000,000 pounds, 
valued at $225,000, besides which over 3,000,000 pounds of saugers, 
worth $75,000, are yearly taken in the same waters. Throughout its 
range it is caught nearly the year round, and, in spite of the zeal with 
which it is pursued on account of its fine table qualities and the ease 



MANUAL OF FISH-CULTURE. 167 

with which it is captured, it is holding its own well owing to its hardi- 
ness, its comparative freedom from disease, and the facility with which 
it is produced by fish-cultural methods. 

As a table article it ranks high. The smaller fish are delicious fried, 
broiled, or boiled, while the larger ones, weighing from 5 to 15 pounds, 
are excellent when baked. The flesh is firm and well flavored, even in 
the warmest weather. Few fish stand shipment, holding, or freezing 
better than pike perch. It is not so well adapted to salting as some 
species, but this is not important, as the demand for it is so great that 
the supply is always disposed of fresh or frozen. The abdominal cavity is 
comparatively small and the head medium, so that little loss occurs in 
dressing. The bones are somewhat numerous, but they are generally 
large and easily separated. The gray and yellow varieties are consid- 
ered superior to the blue for food, and are also better game fish. 

The pike perch, although capricious, is readily caught with baited 
hook, artificial fly, spoon, etc., and deserves high rank as a game fish. 
About 100 tons are taken annually with hook and line through the ice 
about the Bass Islands, Lake Erie; large quantities are also thus 
caught near Buffalo, N. Y., in Saginaw Bay, Mich., and elsewhere. In 
ice fishing small minnows are generally used, the bait being taken near 
the bottom. 

FEEDING HABITS. 

Although the pike perch is predaceous, observations would seem to 
show that it devours fewer desirable species than any other predatory 
fish. Its main food in Lake Erie the year round is a small cyprinoid, 
usually called lake shiner, which abounds in these waters, with occa- 
sionally crawfish in the winter and the larvae of insects and the insects 
themselves in the warmer months. A pike perch weighing 16£ pounds 
has been caught containing a bullhead which in its partly digested 
condition weighed 9 ounces. The stomachs of hundreds have been 
opened at all seasons of the year and under various conditions, and 
the examinations have as yet failed to disclose one containing a white- 
fish, black bass, or other valuable fish. Usually the stomach was empty 
so far as the unassisted eye could discover, except for a thick, tough, 
greenish-yellow slime. 

The pike perch does not generally inhabit the depths of waters fre- 
quented by the black bass, preferring the deeper portions of the shal- 
low parts of the lake. Excepting the blue pike variety, it is not found 
in deep water, which is the home of the whitefish during all the year 
except for a short period in the fall during its reproductive migrations. 
And even the blue pike does not inhabit the deep waters where the 
whitefish and cisco spend most of their lives. 

SPAWNING AND SPAWN-TAKING. 

The pike perch is not a nest-builder, as are the basses and sun fishes. 
The female discharges her spawn in shoal waters, the male following 
and emitting milt in proximity to the eggs. The spawning time varies 



168 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 

greatly in different localities, extending from the last of March with 
the yellow and gray varieties to the latter part of May. The blue pike 
has not been hatched by fish culturists, and comparatively little is 
known of its spawning habits. 

The work of collecting eggs for artificial propagation generally 
begins about the 10th of April and extends to the 25th of that month. 
The eggs are obtained from fish taken by commercial fishermen. Half 
or more of these are hatched into vigorous fry and deposited in public 
waters, and but for this work all the eggs thus saved would go to the 
market in the abdomens of the fish and be entirely lost. 

The pike perch develops a greater number of eggs in proportion to 
its weight than the whitefish, and but a small percentage of them are 
fertilized under natural conditions. The eggs are 0.08 inch in diameter 
and average about 150,000 to a fluid quart. About 90,000 eggs would 
probably be a fair average per fish for Lake Erie, and as the spawning 
fish will average about 2 pounds each, 45,000 eggs to the pound weight 
of fish would approximate the true figures. 

As the spawning time approaches spawn-takers are stationed at the 
various points on the lake where nets are to be fished. A spawn- taker 
accompanies the fisherman on his trips to the nets and examines the 
catch for ripe fish. His equipment is the same as that described in 
the chapter on whitefish, except that he takes a quantity of swamp 
muck for use in preventing adhesion of the eggs. After he has selected 
and stripped a fish, it is returned to the fisherman. The eggs after 
being fertilized are either shipped directly to the hatchery or through 
some central collecting station. 

The inner membranes of the egg are delicate and easily ruptured, 
and the greatest care is necessary, from the taking of the spawn to the 
hatching of the fry, and especially until they are cushioned by the 
filling of the membranes with water. 

The fish should be wiped so that slime will not drip into the spawn- 
ing pan, as a very small portion will clog the micropile and prevent 
impregnation. The female is grasped firmly in the left hand just for- 
ward of the tail, with the back of the hand downward, the fingers 
outward and the thumb above and pointing upward, the head of the 
fish being held between the spawn-taker's right wrist and body, the 
right hand grasping the fish from below, just back of the pectoral fins, 
the fingers inward, the thumb outward. The anterior portion of the 
abdomen is thus firmly grasped and the pressure brought to bear on 
the eggs in the ovaries of the fish. A woolen mitten ou the left hand 
allows a firmer grasp ou the slippery body than is possible with the 
bare hand. The fish is now at an angle of 45°, the body forming a 
modified crescent, with the vent within 2 or 3 inches of the bottom of 
the pan. This position throws the pressure on the abdomen and 
facilitates the opening of the vent and the flow of the eggs. Gentle 
pressure is now maintained as long as the eggs come freely and in a 



MANUAL OF FISH-CULTURE. 169 

fluid stream, probably over half of them being procured before the 
baud is moved, but when the flow slackens, and not until then, the hand 
should be moved slowly toward the vent without releasing the pressure 
and only fast enough to keep the eggs flowing in a continuous stream. 
When this stops the hand should be replaced and the process repeated 
until all the good eggs are procured. If the eggs do not start readily 
they should not be taken. 

As soon as one female is stripped the milt is added, care being taken 
all the time to allow no water in the pan until the lot is finished or 
until the pan is half or two-thirds full of eggs. If males are abundant 
one is stripped for each female, and one for every two or three females 
in any event. When the pan is about half full, and before any water 
is added, the eggs are very thoroughly and carefully stirred with the 
outstretched, spread fingers, and enough water is added to incorporate 
the egg mass and nicely cover the eggs, the whole being mixed again 
with the fingers and allowed to stand for 2 minutes. Next the milt of 
one or two more males and a little water are added, the mixture is 
stirred as before, and again allowed to stand for 5 minutes. 

Impregnation can not take place unless the milt and eggs come into 
perfect contact, and as the milt dies 2 minutes after water is added, 
and as the eggs will not become impregnated after having been in 
water 6 minutes, it can readily be seen that the eggs and milt must be 
thoroughly and quickly mixed, both before and after the water is 
added. A tablespoonful of muck solution is now stirred into the mass 
and a pint of water added. The water is poured off after standing and 
this process is repeated every half hour, as described on pp. 174-175. 

After the adhesion has subsided the eggs are placed in a keg nearly 
filled with water and stirred every half hour, with a change of water 
at least every hour from the time the eggs are taken until they are 
delivered at the station. The stirring is thoroughly, but gently, done 
with a dipper, care being taken that the dipper does not strike the 
sides or bottom of the keg. 

The eggs should never be exposed to the sun, and the water sur- 
rounding newly taken eggs should preferably be kept between 40° and 
50° F. ; in fact, experience has shown that even 35° is not harmful. 
Of course, all sudden changes of temperature should be avoided. 

DEVELOPMENT AND CARE OF EGGS. 

When the eggs arrive at the station they are held in 15-gallon cans 
for about 24 hours, a gentle stream flowing into each can, this being 
considered better than to place them at once in the hatching-jars, where 
the motion is too violent for the green eggs. While thus held they are 
stirred every hour. Kegs or cans may be carried half full of eggs if 
properly cared for. 

For the handling of all eggs at Put-in Bay, except those to be shipped 
by rail or wagon, 15 gallon pine kegs, painted outside, with iron hoops 
and iron drop handles, are preferred to tin cans. They are cheaper, 



170 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 

lighter, more durable and convenient. The eggs are in full view when 
being stirred and when water is poured off or added; the most impor- 
tant point, however, is that the kegs retain the water at a more even 
temperature, as they are less affected by heat and cold thau the cans. 
All dishes and implements with which the eggs come in contact should 
be thoroughly scalded and cleaned at the beginning and close of each 
egg taking season. 

For hatching pike-perch eggs at Put-in Bay the same jars are used 
as for the whitefish eggs, and on pp. 115-110 will be found a description 
of the hatchery and its equipment, the arrangement of the jars in a 
" battery," the manner of operating them, etc. The pike-perch eggs 
are lighter than many others, and, being hatched in comparatively 
warm water, fungus quickly when dead. The water used in hatching 
them should therefore be practically clear, for if it contains any con- 
siderable portion of silt the fungused eggs will soon become so loaded 
as to possess the same specific gravity as the living ones, and sink in 
the egg mass, forming lumps which can be removed only by screening, 
which is always more or less injurious. Even the live eggs will become 
coated, interfering with the proper working of the jars. Where clear 
water is used the fungused eggs remain buoyant, keep on top of the egg 
mass, and are easily removed without loss or injury to the live ones. 

Where water is ouly moderately turbid and a large number of eggs 
are being handled, if the water temperature runs up to 55° or 00° the 
eggs will fungus so rapidly that they can not be separated fast enough 
to prevent the live eggs from becoming mixed with them. As it is 
practically impossible to run "hospital jars" under such conditions, 
many eggs must be lost, or the small percentage of live ones contained 
in the mass of dead ones must be drawn off and distributed in the lake 
and thus given a chance there to hatch. Both of these conditions are 
to be deprecated and can be prevented by a filtering plant. 

In order to insure perfect cleanliness, it is advisable to treat the 
whole system of troughs and pipes through which the water runs, once 
or twice a year, with a clear solution of chloride of lime,, beginning 
with the supply tanks, which should be thoroughly washed inside, and 
following down until all have been reached, opening each faucet or 
cock during the procedure. In this way, at small expense, the system 
is freed from infusoria and other forms, which at times are very 
troublesome and more or less destructive to the eggs. This work 
should be done in the fall, just before whitefish eggs are to be placed 
in the jars, and again in the spring, as soon as the whitefish eggs and 
fry are all disposed of and before the pike-perch eggs are received. If 
these periods overlap, a battery at a time can be treated. After treat- 
ment, the tanks are thoroughly washed and the whole system is flushed 
for an hour or more. Chloride of lime is much more effective for this 
purpose than common lime. The preparation is made by dissolving 5 
pounds of chloride of lime in 10 gallons of water, and after it has settled 
the clear solution is decanted off and added to many times its bulk. 



Fish Manual. (To face page 170.) 



Plate 52. 




PHOTO-MICROGRAPHS SHOWING PHASES OF CANNIBALISM AMONG PIKE-PERCH FRY. 



MANUAL OF FISH-CULTURE. 171 

The fry of the pike-perch are only about as large round as ordinary 
sewing thread and about - x \ inch long; it therefore requires very fine 
brass- wire-cloth screens to hold them in the tanks, and it is exceedingly 
important that these screens be kept clear — preferably by the air jets 
described in the chapter on whitefish (p. 119). This apparatus gives 
perfect satisfaction and twice the number of whitefish or pike-perch 
fry can be successfully carried in a given amount of water with the air 
system than without its aid. 

When the eggs are placed in the jars 24 hours after taking, allow- 
ance is made for some additional swelling, and accordingly 3£ quarts 
of eggs are placed in each jar on setting them up. These will swell 
to 1 or 4^ quarts at the end of 3 days, and that number works best. 
The eggs are worked with the least possible amount of water that will 
keep them in motion throughout, and anything beyond this is harmful 
and will result in ruptured yolks. The jars are inspected daily, and 
one that is working too fast or is not working uniformly is carefully 
adjusted. 

The eggs are semibuoyaut and very adhesive. A single large, spher- 
ical oil-drop floats at the top of the yolk mass. The germinal disk is 
on the side of the yolk. The first cleavage of the disk ordinarily takes 
place in 5 to 6 hours in a water temperature of 45° to 50° F. Unequal 
division of the disk is rare, although it sometimes occurs, while with 
the whitefish and many other species inequality of cleavage is the 
almost universal rule. 

In a water temperature of 45° to 50° the form of the embryo may be 
distinguished under a low-power glass in 4 days, and the eye-specks 
can be seen by the unassisted eye in about 6 days. By this time the 
pigment cells, or color stars, can also be seen with a microscope of mod- 
erate power, as well as the pulsations of the heart and the coursing of 
the blood through the vessels — the red corpuscles being distinguishable. 

At this stage any monstrosities, malformations, and other blemishes 
may be easily discovered. They consist of embryos with double heads, 
the most common form, more than the normal number of eyes, curved 
spines, and various other deformities, some so slight as to be scarcely 
discernible. All these erratic forms perish before hatching or soon 
afterwards, and cause the loss of a large percentage of the eyed eggs, 
which die before hatching; insufficient food supply in the yolk causes 
the loss of the next greatest number, the two covering about 60 per 
cent of the whole loss of eyed eggs. 

The eggs hatch in from 7 to 28 days, a mean temperature of about 
57° producing the first result and about 40° the latter, neither extreme 
furnishing the best of fry. At a temperature of about 48° the eggs 
will hatch in 18 to 20 days and produce vigorous, healthy fry. 

The absorption of the food-sac is governed by the period of incuba- 
tion and in some measure by the water temperature, and a day or two 
after its complete absorption cannibalism will begin. If 28 days have 
been required the sac will be absorbed in from 5 to G days, while if a 



172 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 

shorter period — say of 14 days — has been required, it will likely take 
10 days before the sac is fully absorbed ami the fry begin to destroy 
each other. 

TRANSPORTATION OF EGOS. 

The best method of shipping eggs a considerable distance before 
hatching is a somewhat open question. The experiment of shipping 
them on trays rather than in water in kegs or cans, as described above, 
has been tried with varying success. If shipped on trays they should 
be accompanied by a watchful messenger, who will see that they are 
not subjected to sudden jars while in transit. They should be spread 
on the trays not over one-third of an inch deep, and should be sprinkled 
lightly every day. The cases containing the eggs should be packed in 
damp sawdust, so that all parts of them will be covered G or more 
inches. Ice should be used if the air temperature is higher than 45° 
or 50° F., as the nearer the eggs can be kept to 40° F. the better. 

Eggs held from 2 to 5 days on trays at Toledo and then shipped 40 
miles by steamer to Put-in Bay came out as well as the average of the 
eggs received near home and held in running water 24 hours. A lot 
shipped on trays from Put-in Bay to Cape Vincent, 1ST. T., about 400 
miles, came out badly, while those from the same lot carried in water 
turned out Avell. This difference is probably accounted for from the 
fact that the eggs carried in water were not subjected to sudden jars, 
while in the other case they doubtless were. It is quite possible that 
failures in shipping pike-perch eggs on trays have been largely owing 
to concussions received during transit, such as must result in carrying 
them on railroad cars and wagons. 

If the eggs are to be transported long distances, they should be 
covered with cheese or mosquito cloth and the remaining space to the 
top of the tray filled with damp sphagnum moss; but if only a distance 
of 75 miles or less is to be traversed, this is unnecessary, care being 
taken to keep the cases right side up. 

Eggs that have been held on trays should be placed in running water, 
in kegs or cans, a few hours before they are put in the jars, or an allow- 
ance of about 12 per cent should be made for shrinkage of the eggs 
while on the trays. Otherwise too many eggs will be put into the jars 
to work well. 

PLANTING THE FRY. 

In order to prevent loss from the fry preying upon each other, when- 
ever practicable they should be planted before the sac is fully absorbed, 
but not for 3 or 4 days after hatching, since if they are so held they 
gain strength, and if they are to be transported some distance, they 
become better fitted for withstanding the hardships of a long journey. 
But with large numbers, running into hundreds of millions, lack of space 
makes it necessary to liberate them almost as fast as hatched Dark- 
ening the tanks prevents cannibalism, but owing to the absence of food 
and possibly to the darkness the fry become weak and light-colored in 



MANUAL OF FISH-CULTURE. 173 

a day or two and will riot stand transportation. They must, therefore, 
be transported before the sac is fully absorbed or large numbers will be 
lost by either cannibalism or starvation. 

During the season of 1899 the water pumped from the lake for the 
supply of the fry tanks at the Put-in Bay Station literally teemed with 
Crustacea, such as Cyclops, Dlaptomas, Daphnia, Alonopsis, etc., but at 
first, after the food-sac was absorbed, the fry refused t > partake of 
these, their supposed natural food, and preyed on each other instead. 
Three or four days later, however, a few hundred fry held for experi- 
mental purposes devoured these Crustacea greedily and throve upon 
them as long as the supply was kept up. When cannibalism was at its 
height 50 fry were placed in a tin pan, with myriads of Crustacea. In 10 
minutes there were 6 cases of cannibalism. In each case one of the fry 
seized the tail of another and swallowed all it could. Close watching 
failed to discover any of these fry attempting to seize one of the Crus- 
tacea. It was also discovered that neither the fry of the whitefish nor 
of the pike perch, when later they began to feed on the Crustacea, would 
touch a Diaptomus, although the most showy of all the Entomostraca 
present and resembling very strongly the Cyclops, with which it is 
closely related. When a hungry fry would, as if by accident, seize a 
Diaptomus it would at once reject it and go about showing unmistak- 
able signs of discomfort. Contrary to the general belief, the fry do not 
always die from the effects of eating other fry. The swallowed portion 
may be digested and the head and attached tissues finally rejected. 

It has been customary to employ the same method in planting pike- 
perch fry as in planting whitefish fry ; that is, the fry are dipped from 
the fry tanks of the hatching battery into cans or kegs and transported 
on a steamer to the points selected, where the cans are carefully 
lowered into the water and the young fish allowed to swim out. 

Toward the close of the season of 1899 au experiment was made of 
carrying fry to the planting-grounds in a tank on board the steamer. 
The tank held 400 gallons, and was therefore equal in capacity to 
forty 10-gallon cans, but it was found in practice that a half more 
fry could be carried in this way with a given amount of water than 
in cans, as there was a continual stream going in through hose con- 
nected with a deck pump and out through screened siphons, whereas 
with cans some must stand while the water in others is being changed. 
Moreover, it is impossible to get a maximum number of fry in each can, 
so that some cans are carried with fewer fry than they should contain, 
while experience soon taught how many could be safely handled in the 
tank. 

The fry were drawn from the fry tanks in the house direct to the tank 
on the steamer through a 1-inch rubber hose, acting as a siphon, the 
suction end being held near the air supply, where fry collect in largest 
numbers. This required 10 to 15 minutes, while by the old method of 
dipping the fry into tubs and then distributing them into the kegs on 
board it would take more than an hour. This saving of time is very 



174 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 

important when fry are hatching rapidly. Another advantage is that 
by passing the hose about close to the bottom of the tank nearly all 
the shells are removed with the fry, thus keeping the tanks compara- 
tively clean. Examinations showed that the fry were not injured by 
passing through the Lose, which is also an advantage over dipping 
them out with scoops. 

On arriving at tbe field of planting, the fry and water are discharged 
through a section of hose about 10 feet long, leading from the bottom 
of the tank. The steamer is kept at a slow speed at the time and the 
transfer of the fry to the water is accomplished as gently at least as 
would be the case in emptying them from kegs. Considerable time, as 
well as much hard work, is saved by this plan, and so far there appears 
to be no objectionable features in it. 

USE OF SWAMP MUCK TO PREVENT ADHESION OF EGGS. 

Many experiments have been made from time to time to determine 
the best means to prevent adhesion in the pike-perch eggs. This may 
be accomplished by constantly stirring the eggs from the time the 
water is added until it fills the egg and adhesion ceases; but this 
causes loss of time and a large percentage of yolks will inevitably be 
ruptured. Another method is to allow the eggs to agglutinate into a 
mass and stand thus until fully hardened, afterwards separating them 
by gently rubbing them between the hands, but this also sacrifices time. 
The date of the first use of foreign, inert substances to prevent adhesion 
is uncertain. Fine clay dust and clay in solution have been used with 
success and experiments with starch have given good results. By a 
series of experiments with eggs taken in the vicinity of the station 
from the boats of the fishermen, and from the penned fish as well, it 
was found that the proper use of swamp muck obviates the difficulty, 
with a great saving of time, labor, and eggs. 

In the spring of 1895 finely divided, washed, and screened swamp 
muck was tried at Put-in Bay and has been used ever since, aud 
recently with complete success, owing to a change in the method of 
application. The plan pursued up to 1899 was to add muck to the 
water in the kegs into which the eggs were poured alter impregnation 
aud to wash them quickly. Tbe washing was done quickly in order to 
prevent adhesion. This was effective, but it involved the use of too 
much muck, which was removed from the water with some difficulty, 
and which smothered the eggs if left in too long in any quantity, and, 
furthermore, it was difficult to get exactly the right quantity of the 
mixture. Careful experiments were therefore made in using the muck 
in the pan immediately after impregnation had taken place and satis- 
factory results were obtained. The eggs are allowed to stand in the 
milt for about 10 minutes with sufficient water to barely cover them, 
being carefully stirred once or twice meanwhile. Then a tablespoonful 
of the muck mixture, of the consistency of thick cream, is added. 
Next the pan is nearly filled with water and stirred thoroughly, when 



MANUAL OF FISH-CULTURE. 175 

it is left half an hour, or while another pan is being filled. Without 
moving pan No. 1 more than is necessary the surplus water is poured 
off, the pan again filled, stirred, and left as before, while pan No. 2 is 
treated like the first. If the boat rocks so as to endanger the safety 
of the eggs it is better to pour them carefully into the keg and let 
them stand there, keeping only about an inch of water over them and 
pouring the water off and adding fresh water at intervals of not more 
than half an hour. 

The important point in preventing adhesion is to leave the eggs 
alone until the particles of muck, or the spermatozoa, in case the eggs 
are held in the milt without the addition of muck, have settled, and 
then pour off the comparatively clear water, adding a fresh supply 
and then gently agitating the eggs. It will be observed that most of 
the mack particles will have settled in one minute, the water becoming 
measurably clear. If the eggs are held in the milt, the water being 
very milky from the mixture, the water will become comparatively clear 
in 3 or 4 minutes. This is because the spermatozoa are slightly heavier 
than the water and settle to the bottom. In either case it is important 
to retain the particles in the remaining water and eggs until adhesion 
has ceased, in order to keep the eggs separated from each other, for 
although the particles of muck or the spermatozoa, as the case maybe, 
are adherent, sticking to the surface of the egg, they are easily washed 
off, thus permitting the eggs to come into contact and become fastened 
together. Aside from the washing oft", the area of the egg membrane 
becomes constantly greater, removing the particles farther and farther 
from each other until finally the surfaces meet and adhesion takes place. 
This will not occur if the muck particles or the milt are left in the egg 
mass until adhesion has ceased or until the egg has become practically 
filled with water — that is, has finished swelling. 

The first great loss of eggs is owing to lack of impregnation, and the 
second, shown by their turning white, is owing to the rupture of the 
sac. While the eggs are soft and not cushioned by the absorption of 
water, the greatest care possible will not prevent the rupture of a con- 
siderable percentage of the sacs where the old method is pursued of 
constant working to prevent adhesion. By holding the eggs in the 
milt — which is better than the old way and requires less labor, but is not 
to be compared with the muck process — or by using muck, with reason- 
able care in all other directions, the loss is very slight, as has been 
shown by careful experiments and counts. 

Muck has proved far superior to starch or any other substance which 
has been tried at the Put-in Bay Station, starch being prone to settle 
into a hard mass among the eggs, requiring considerable work to again 
dissolve it, with more or less injury to the eggs. 

The preparation of the muck solution is very simple, but should be 
carefully conducted, as follows: 

At a suitable place in a swamp a depression is dug, which quickly 
fills with water. Muck is now suspended in this water by thorough 



176 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 

beating and stirring until most of the muck particles are freely divided. 
Care is taken not to get the mixture too thick, as the sand will not 
settle out nor can the mixture be screened freely. This is poured 
through a screen placed across a washtub until the tub is full, when 
the debris is knocked off the top of the screen and another tub is filled. 
The partially clear water is ponred off of tub No. 1, it is again filled 
with muck, and this is continued until there are a few quarts of muck 
of the consistency of cream in the bottom of the tubs. The tubs are 
next filled with water, which is agitated thoroughly, and then allowed 
to stand a few seconds to give the particles of sand time to settle. 
The contents of the tubs are then emptied into kegs or cans, when the 
water may be poured off in an hour or more. This leaves quite a thick 
mixture of even consistency, as' shown under the microscope. It should 
be free from sand, which would collect in patches in the bottom of the 
jars and interfere with the working of the eggs. 

It is very necessary that the muck be now thoroughly cooked or 
scalded, otherwise infusoria will develop on the eggs, causing much 
inconvenience and some loss. Finally the muck is drained off, dried in 
any desired form, and held ready for use. It should be prepared before 
the egg-collecting season begins. The screen is about 20 inches by 30 
inches and is made by tacking to a wooden frame a fine wire cloth of 
40 meshes to an inch. The finest mesh that will let small particles of 
muck through is best. The cloth is bagged down somewhat, with the 
tack heads up, in order to present a smoother surface for the quick 
cleaning of the screen. 

PENNING FISH. 

The plan of holding in pens adult fish taken prior to the spawning sea- 
son has been tried with pike perch as well as with whitefish. This is 
done to insure a sufficient and definite number of spawners, the collec- 
tion of which during the spawning season is sometimes interfered with by 
stormy weather or other causes. Contrary to what would be naturally 
expected, the pike perch is much more difficult to handle in this way 
than the whitefish, probably owing to the higher temperature of the 
water at the time the work is carried on. Fewer can be transported in 
the tanks on board of steamers and fewer can be held in the pens. 
Where injuries have occurred fungus is apt to set in much earlier than 
with the whitefish, and on this account excessive care is necessary in 
handling pike perch, as well as to prevent injury to eggs in the ovaries. 
While the male whitefish can be held and used over for two or three 
days, the pike perch can be used but once, and when held for several 
days, especially late in the season, the milt comes from the fish thick- 
ened as if taken from a dead fish, and is far from being at its best. 
However, this is true to a great extent with the fish taken fresh from 
the nets late in the season. Females which do not "ripen" within two 
or three days are likely not to furnish eggs at all, and if held even two or 
three days late in the season are likely to yield eggs which will not hatch. 



MANUAL OF FISH-CULTURE. 177 

Pike perch are obtained iu the same manner as the whitefish, from 
the pound nets of the fishermen. They are sometimes taken directly 
into the tanks on board the steamer from the pound when it is raised, 
but more often are dipped into supplemental nets by an employee of the 
Commission, who accompanies the fishermen when the pound is lifted, and 
are held until they can be picked up at leisure by the steamer. This 
permits the gathering offish from many nets, while if they were taken 
directly from the pound ouly one lifting- boat can be followed at a time 
and comparatively few fish collected. The supplemental nets are 
placed at each pound net where fish are expected. They are 3 feet in 
diameter and 7 feet in depth, and are held open at top and bottom by 
rings of half-inch iron, the bottoms being provided with puckeriug- 
strings to close them. The top ring is fastened to the outhaul stake 
and rim line of the pound, the lower one hanging free and acting as a 
weight to hold the end in place, and also serving to keep the net open 
so that the fish will have plenty of room and not be scaled by chafing 
against the meshes. When thus located, the supplemental net is in a 
convenient position for receiving the fish when the pound is lifted. 
Rowboats transfer the fish in tubs to the steamer, where they are placed 
in tanks and transported to the pens, where they are counted and 
assorted according to their ripeness. 

The pens or live-boxes used iu the pike-perch work are the same as 
those used for whitefish. Stationary live-boxes, supported by piling, 
have been used, but as the water at Put-in Bay becomes too warm for 
this, the boxes are now made so that they can be towed, like a raft, into 
open waters where the current is more vigorous and the temperature 
more uniform. Another advantage gained by this method is that an 
equal depth of water is maintained in the live boxes, the rise and fall 
in this section varying from 4 to 5 feet in a single day, according to 
the direction and velocity of the wind and the atmospheric pressure. 
The boxes are 10 feet long, 8 feet wide, and 8 feet deep, divided into 
two equal compartments 8 feet square, provided with false bottoms 
controlled by standards running in guides at the ends. The standards 
are pierced by inch holes at intervals of G inches, so that the false 
bottoms may be held at auy desired place. 

The pens, in groups of five, are fasteued end on between booms, and 
the whole thus forms a raft. The booms are made of 4 by 8 hemlock 
joists, 2 feet apart on the outside, trussed at frequent intervals by 
diagonal cross braces and ties, on top of which are placed two tiers of 
1-foot wide hemlock planks, thus making the booms when completed 
52,feet long, 2 feet wide, and 1 foot deep, and quite strong and rigid, 
capable of withstanding seas of considerable violence. At each end 
and between all the crates are placed 2-foot plank walks, giving ample 
room for working on all sides, which is a great convenience in handling- 
fish and procuring eggs, especially in stormy weather. The pens are 
now made of boards •'{ inches wide, nailed 1£ inches apart, which gives 
sufficient space for free circulation of water. The lumber is dressed 

F. M. 12 



178 REPORT OP COMMISSIONER OF FISH AND FISHERIES. 

ou all sides and all inside corners are rounded, as the fish injure 
their noses on square corners in their attempts to escape. All parts of 
the pens are interchangeable and easily taken down for storage, being 
held in place by 4-iuch log bolts. The pens are fastened to the booms 
by log bolts 6 inches long. 

Much depends on the work of transporting either whitefish or pike 
perch from the nets to the pens, not only in moving the fish with the 
least possible injury, but in the saving of time, so that greater numbers 
may be penned and the risk of holding the fish in the supplemental 
nets may be minimized. Tow cars have been used, but they retard the 
speed of the steamer fully one-half, and tanks on the decks of the 
steamers have therefore been adopted. It is better to have several 
smaller tanks than one large one, as the fish can be dipped more readily 
from the small tanks and the water is not so violently agitated during 
rough weather. A convenient size is about 6 feet long, 4 feet wide, and 
3 feet deep. The tank has two lids, submerged about an inch, arranged 
to open crosswise of the center and held by lugs below and by pins 
above. The lids are made of 3- inch boards nailed firmly upon cleats on 
the upper side, with about ^-inch space intervening. This prevents 
slopping in any weather when fish should be handled. The tank is 
smooth and it has no obstructions inside. A 2-inch hole at the bottom 
at one end is provided for drawing off water, and one of the same size 
within 3 inches of the top for an overflow, when fresh water is being 
added. Fresh water must be furnished, varying as to the number of 
fish. This can be supplied with a "donkey-pump," the hose being 
carried from one tank to another as required. With three tanks of the 
dimensions given above, six or seven hundred pike perch of average 
size can be transported. 

For coating these tanks inside, as well as all tanks and troughs about 
the hatchery, coal tar with about one-third its bulk of good spirits of 
turpentine, free from benzine, is applied as hot as it can be made. 
This forms a smooth, hard, strong, impervious coat which lasts well, 
and is cheaper than asphaltum varnish. 

The use of a proper dip net in handling the fish is of great impor- 
tance. The splitting of fius and removing of scales is to be avoided as 
far as possible where any species of fish is to be x>enned. The scales 
of the pike perch are not so easily abraded as those of the whitefish, 
but it suffers even more as the result of injuries, owing to the higher 
temperature of the water at the time it is penned. The ideal net would 
be made of cofferdam rubber of suitable thickness, perforated at fre- 
quent intervals so as to permit the free discharge of the water — that is, 
a rubber net — but where many are necessarily in use and subject to 
rough handling, especially in freezing weather, their expense would be 
considerable. The hoop of the net used at the Put in Bay station is of 
finch spring steel wire, that being the stiffest and strongest material 
obtainable of its weight. It is bent in the form of a parallelogram 22 
inches long and 20 inches wide, with rounded corners. This is fastened 



MANUAL OP FISH-CULTURE. 179 

into an ash handle about 6 feet long. The bag is of cider-press cloth 
(which is made of large, soft twisted thread, loosely woven), with each 
alternate thread Over a considerable space in the center of the net 
palled out. The bag is fastened to the hoop with small copper wire, as 
twine is soon cut off in working around the nets and pens. The bag 
of the net is 8 or 10 inches, for if much more is given it will let the fish 
form a pocket against the wire and prevent an easy discharge. 

Netting with a 1-inch mesh and large thread has proved to be a fail- 
ure, the tails of many fish being split by it. It is believed that netting 
with a very small mesh and the largest thread that can be woven will 
do the work well, the greatest objection being the knots, which injure 
tender species. 

A frame made like a stretcher, with gunny cloth tacked on in such a 
manner as to bag about 2 feet, is convenient for holding fish preparatory 
to spawn-taking. It should be about 6 feet long and 3 feet wide, making 
the bag 3 by 4 feet, with handles 1 foot long at each end. 

A gate made of light stuff as long as the pens are wide (8 feet) 
and 2 feet deep, covered by ordinary netting drawn taut and fastened by 
small staples, is useful in sorting the fish in the pens. The false bottom 
is lifted and fastened in place with the pins. There will now be about 
a foot of water over the floor and 1 foot of the top of the pen will be 
out of water. Beginning at one side the gate is gently moved along until 
the fish are all confined in a sufficiently restricted space. They are 
sorted, the ripe fish placed in the "stretcher," preparatory to stripping 
them, the medium in a tub to be taken to the proper pen, and the hard, 
which it is assumed will be in the majority, are put back over the gate 
into the same pen they were taken from. 

The pens are numbered and a careful memorandum kept of the fish, 
the number of males and females received from and turned back to the 
fishermen each day, the number stripped, and the number in each pen. 

All unnecessary noise near the pens must be avoided, especially jars 
or discharge of firearms, and no one should go near them except in 
the performance of duty. The quieter fish are kept and the less and the 
more gently they are handled the greater the chances of procuring a 
large number of good eggs, while the opposite course will cause many, 
"plugged" females and failure generally. In transferring the fish from 
one net or receptacle to another it is preferable to handle only one at a 
time, except when they are small. 

Fish, particularly females, taken from a depth of from 30 to 35 feet, 
often come to the surface of the water in the pens and can not descend, 
owing to the expansion of air in the swimming bladder. The pressure 
may be relieved without injury by inserting a small-sized aspirating 
needle, at an angle of about 45°, through the flesh of the fish into the 
bladder, about halfway between the middle of the spinous dorsal and 
the lateral line. The air can be heard escaping and when the sound 
ceases the needle may be removed. 



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